Polymer compositions and coating solutions

ABSTRACT

In a first aspect, a polymer composition includes a first polymer derived from a soluble polymer composition having an imide group and a Tg reducing compound having an amine group. The first polymer has a glass transition temperature that is lower than a second polymer derived from the same soluble polymer composition, but without a Tg reducing compound having an amine group. In a second aspect, a coating solution includes a soluble polymer having an imide group and a Tg reducing compound having an amine moiety that can be an amine or a first masked amine that can be converted to an amine, wherein the first masked amine can be chemically converted, thermally converted, photo-converted or dissociated.

FIELD OF DISCLOSURE

The field of this disclosure is polymer compositions and coatingsolutions.

BACKGROUND OF THE DISCLOSURE

Polyimide compositions are used as films and shaped bodies due to theirgood electrical insulating properties, mechanical strength, hightemperature stability, and chemical resistance properties. Polyimidefilms are adhered to thin metal foils to form metal-clad laminates andfind broad usage for die pad bonding of flexible print connectionboards, semiconductor devices or packaging materials for chip scalepackage, chip on flex, chip on lead, lead on chip, multi-chip module,ball grid array (or micro-ball grid array), and/or tape automatedbonding, among other applications.

U.S. Pat. No. 7,285,321 describes a multilayer laminate having a lowglass transition temperature (T_(g)) polyimide layer, a high T_(g)polyimide layer, and a conductive layer. The high T_(g) polyimide layeris a thermoset polyimide, and the low T_(g) polyimide layer is athermoplastic polyimide. Using a lower T_(g) layer next to the metallayer improves the adhesion of the polyimide to the metal. U.S. Pat. No.6,379,784 describes an aromatic polyimide laminate composed of anaromatic polyimide composite film, a metal film and a release film. Thearomatic polyimide composite film is composed of an aromatic polyimidesubstrate film and two thermoplastic aromatic polyimide layers. Themetal film and the release film are adhered to opposite sides of thearomatic polyimide laminate without the use of additional adhesivelayers, with good adhesion between the polyimide laminate and the metalfilm.

Inorganic (e.g., ceramic and glass) laminated products have long beenused for a wide variety of applications, such as armor for buildings,vehicles and personnel, as well as safety glass for transparentapplications. Beyond the well-known, every day automotive safety glassused in windshields, laminated glass is used as windows for trains,airplanes, ships, and nearly every other mode of transportation. Safetyglass is characterized by high impact and penetration resistance anddoes not scatter glass shards and debris when shattered.

Safety glass typically consists of a sandwich of two glass sheets orpanels bonded together with an interlayer of a polymeric film or sheet,which is placed between the two glass sheets. One or both glass sheetsmay be replaced with optically clear rigid polymeric sheets, such assheets of polycarbonate materials. Safety glass has further evolved toinclude multiple layers of glass and polymeric sheets bonded togetherwith interlayers of polymeric films or sheets.

The interlayer is typically a relatively thick polymer sheet, whichexhibits toughness and bondability to provide adhesion to the glass inthe event of a crack or crash. In general, it is desirable that thesepolymeric interlayers possess a combination of characteristics includingvery high optical clarity, low haze, high impact resistance, highpenetration resistance, excellent ultraviolet light resistance, goodlong-term thermal stability, excellent adhesion to glass and other rigidpolymeric sheets, low ultraviolet light transmittance, low moistureabsorption, high moisture resistance, and excellent long termweatherability, among other requirements.

A recent trend has been the use of glass-laminated products in theconstruction of homes and office structures. The use of architecturalglass has expanded rapidly over the years as designers incorporate moreglass surfaces into buildings. Threat resistance has become anever-increasing requirement for architectural glass laminated products.These newer products are designed to resist both natural and man-madedisasters. Examples of these needs include the recent developments ofhurricane resistant glass, now mandated in hurricane susceptible areas,theft resistant glazings, and the more recent blast resistantglass-laminated products designed to protect buildings and theiroccupants. Some of these products have great enough strength to resistintrusion even after the glass laminate has been broken; for example,when a glass laminate is subjected to high force winds and impacts offlying debris, which can occur in a hurricane, or where there arerepeated impacts on a window by a criminal attempting to break into avehicle or structure.

A smooth glass surface presents a challenge for adhering a polymer layerwithout the use of adhesives. Silanization is a well know method forintroducing a variety of functional groups onto a glass surface. Forexample, a coating solution having an amino-functional silane couplingagent can be deposited onto a glass substrate and dried to remove thesolvent, resulting in a glass surface with a modified surface energy.

Polyimide films can be adhered to inorganic substrates, such as siliconsubstrates, by coating a polyamic acid solution onto a silicon substratethat has been functionalized using an amino-functional silane couplingagent (A. V. Patsis and S. Cheng, J Adhesion (1988), 25, 145-157). Whenthe solution is applied to the treated surface, the silane couplingagent interacts with the amic acid through interactions betweencarboxylic acid and amine groups on the polyamic acid and silanol groupson the silicon substrate. During subsequent curing, the polyamic acid isconverted to the polyimide. Similarly, metal-clad laminates can be madeby coating a polyamic acid solution onto a metal foil and subsequentlycuring and imidizing the polyamic acid to form a polyimide film.

DETAILED DESCRIPTION

In a first aspect, a polymer composition includes a first polymerderived from a soluble polymer composition having an imide group and aglass transition temperature (T_(g)) reducing compound having an aminegroup. The first polymer has a glass transition temperature that islower than a second polymer derived from the same soluble polymercomposition, but without a T_(g) reducing compound having an aminegroup.

In one embodiment of the first aspect, the second polymer has a glasstransition temperature of 300° C. or less.

In one embodiment of the first aspect, a difference between the glasstransition temperatures of the first and second polymers is 5 degrees ormore.

In one embodiment of the first aspect, the soluble polymer compositioncomprising an imide group is selected from the group consisting ofpolyimides, poly(amide-imides), poly(ether-imides), poly(ester-imides),copolymers comprising amide, ester or ether groups, and mixturesthereof.

In one embodiment of the first aspect, the soluble polymer compositionis derived from a dianhydride, a fluorinated aromatic diamine and analiphatic diamine.

In one embodiment of the first aspect, the dianhydride comprises analicyclic dianhydride.

In one embodiment of the first aspect, the T_(g) reducing compoundcomprises an amine moiety comprising an amine or a first masked aminethat can be converted to form an amine, wherein the first masked aminecan be chemically converted, thermally converted, photo-converted ordissociated. In one specific embodiment, the amine is a monoaminepolyetheramine. In another specific embodiment, the first masked amineis selected from the group consisting of carbamates, N-alkyl amines,N,N-dialkyl amines, N-aryl amines, N,N-diaryl amines, benzyl amines,amides, sulfonamides, ammonium salts made from acids and silylderivatives. In still another specific embodiment, the T_(g) reducingcompound further comprises one or more additional amine moieties havingone or more additional masked amines that can be converted to formamines; and the one or more additional masked amines can be chemicallyconverted, thermally converted, photo-converted or dissociated.

In one embodiment, a polymer film comprises the polymer composition ofthe first aspect. In a specific embodiment, a metal-clad laminatecomprises the polymer film and a metal layer.

In another specific embodiment, an article comprises the polymer filmand an inorganic substrate, wherein the inorganic substrate comprises amaterial comprising a ceramic, a glass, a glass-ceramic or a mixturethereof, wherein the material comprises: a metal cation selected fromthe group consisting of silicon, aluminum, titanium, zirconium,tantalum, niobium and mixtures thereof; and oxygen.

In a more specific embodiment of the article, the inorganic substratecomprises glass.

In another more specific embodiment of the article, the metal cationcomprises silicon.

In still another more specific embodiment of the article, the articlehas a b* of 1.25 or less and a yellowness index of 2.25 or less whenmeasured using the procedure described by ASTM E313 at a thickness of 25μm.

In still yet another more specific embodiment of the article, thearticle has a haze of 15% or less and an L* of 93 or more when measuredat a thickness of 25 μm.

In another more specific embodiment of the article, the article furthercomprises a hard coat layer adhered to the polymer film layer on a sideopposite the inorganic substrate.

In one embodiment, an impact-resistant article comprises the article.

In one embodiment, a penetration-resistant article comprises thearticle.

In one embodiment, a sound-reducing article comprises the article.

In a second aspect, a coating solution includes a soluble polymer havingan imide group and a T_(g) reducing compound having an amine moiety thatcan be an amine or a first masked amine that can be converted to anamine, wherein the first masked amine can be chemically converted,thermally converted, photo-converted or dissociated.

In one embodiment of the second aspect, the first masked amine isselected from the group consisting of carbamates, N-alkyl amines,N,N-dialkyl amines, N-aryl amines, N,N-diaryl amines, benzyl amines,amides, sulfonamides, ammonium salts made from acids and silylderivatives.

In a specific embodiment, a carbamate is thermally cleavable and athermally cleavable carbamate is selected form the group consisting oftert-butyloxycarbonyl, fluorenylmethoxycarbonyl, and benzyl carbamate.In a more specific embodiment, the tert-butyloxycarbonyl is selectedfrom the group consisting of N-Boc-1,6-hexanediamine andtrans-N-Boc-1,4-cyclohexanediamine.

In another specific embodiment, a carbamate is photo-cleavable and aphoto-cleavable carbamate is selected from the group consisting of3,5-dimethoxybenzyl carbamate, m-nitrophenyl carbamate, ando-nitrobenzyl carbamate.

In another specific embodiment, an amide is selected from the groupconsisting of formamide, trifluoroacetamide, trichloroacetamide,chloroacetamide, phenylacetamide, 3-phenylpropanamide,3-pyridylcarboxamide, N-benzoylphenylalanyl, and benzamide.

In another specific embodiment, an amide can be thermally cleaved,chemically cleaved, photo-cleaved, dissociated or a mixture thereof.

In another specific embodiment, an ammonium salt is made from an acidselected from the group consisting of acetic acid, butyric acid, pivalicacid, hydrochloric acid, and sulfuric acid; and the ammonium salt can bethermally dissociated.

In another embodiment of the second aspect, the T_(g) reducing compoundis selected from a single multi-functional precursor, a combination ofmultiple single-functional precursors, or a mixture thereof.

In still another embodiment of the second aspect, the soluble polymer isselected from the group consisting of polyimides, poly(amide-imides),poly(ether-imides), poly(ester-imides), copolymers comprising amide,ester or ether groups, and mixtures thereof.

In yet another embodiment of the second aspect, the T_(g) reducingcompound further comprises one or more additional amine moieties havingone or more additional masked amines, wherein the one or more additionalmasked amines can be chemically converted, thermally converted,photo-converted or dissociated.

Depending upon context, “diamine”, when used herein to describe monomersused to form a polymer backbone is intended to mean: (i) the unreactedform (i.e., a diamine monomer); (ii) a partially reacted form (i.e., theportion or portions of an oligomer or other polymer precursor derivedfrom or otherwise attributable to diamine monomer) or (iii) a fullyreacted form (the portion or portions of the polymer derived from orotherwise attributable to diamine monomer). The diamine can befunctionalized with one or more moieties, depending upon the particularembodiment selected in the practice of the present invention.

Indeed, the term “diamine” is not intended to be limiting (orinterpreted literally) as to the number of amine moieties in the diaminecomponent. For example, (ii) and (iii) above include polymeric materialsthat may have two, one, or zero amine moieties. Alternatively, thediamine may be functionalized with additional amine moieties (inaddition to the amine moieties at the ends of the monomer that reactwith dianhydride to propagate a polymeric chain). Such additional aminemoieties could be used to crosslink the polymer or to provide otherfunctionality to the polymer.

Similarly, the term “dianhydride”, when used herein to describe monomersused to form the polymer backbone is intended to mean the component thatreacts with (is complimentary to) the diamine and in combination iscapable of reacting to form an intermediate (which can then be curedinto a polymer). Depending upon context, “anhydride” as used herein canmean not only an anhydride moiety per se, but also a precursor to ananhydride moiety, such as: (i) a pair of carboxylic acid groups (whichcan be converted to anhydride by a de-watering or similar-typereaction); or (ii) an acid halide (e.g., chloride) ester functionality(or any other functionality presently known or developed in the futurewhich is) capable of conversion to anhydride functionality.

Depending upon context, “dianhydride” can mean: (i) the unreacted form(i.e. a dianhydride monomer, whether the anhydride functionality is in atrue anhydride form or a precursor anhydride form, as discussed in theprior above paragraph); (ii) a partially reacted form (i.e., the portionor portions of an oligomer or other partially reacted or precursorpolymer composition reacted from or otherwise attributable todianhydride monomer) or (iii) a fully reacted form (the portion orportions of the polymer derived from or otherwise attributable todianhydride monomer).

The dianhydride can be functionalized with one or more moieties,depending upon the particular embodiment selected in the practice of thepresent invention. Indeed, the term “dianhydride” is not intended to belimiting (or interpreted literally) as to the number of anhydridemoieties in the dianhydride component. For example, (i), (ii) and (iii)(in the paragraph above) include organic substances that may have two,one, or zero anhydride moieties, depending upon whether the anhydride isin a precursor state or a reacted state. Alternatively, the dianhydridecomponent may be functionalized with additional anhydride type moieties(in addition to the anhydride moieties that react with diamine toprovide a polymer). Such additional anhydride moieties could be used tocrosslink the polymer or to provide other functionality to the polymer.

Any one of a number of polymer manufacturing processes may be used toprepare polymer compositions for films and shaped bodies. It would beimpossible to discuss or describe all possible manufacturing processesuseful in the practice of the present invention. It should beappreciated that the monomer systems of the present invention arecapable of providing the above-described advantageous properties in avariety of manufacturing processes. The compositions of the presentinvention can be manufactured as described herein and can be readilymanufactured in any one of many (perhaps countless) ways of those ofordinarily skilled in the art, using any conventional ornon-conventional manufacturing technology.

Although methods and materials similar or equivalent to those describedherein can be used in the practice or testing of the present invention,suitable methods and materials are described herein.

When an amount, concentration, or other value or parameter is given aseither a range, preferred range or a list of upper preferable values andlower preferable values, this is to be understood as specificallydisclosing all ranges formed from any pair of any upper range limit orpreferred value and any lower range limit or preferred value, regardlessof whether ranges are separately disclosed. Where a range of numericalvalues is recited herein, unless otherwise stated, the range is intendedto include the endpoints thereof, and all integers and fractions withinthe range. It is not intended that the scope of the invention be limitedto the specific values recited when defining a range.

In describing certain polymers, it should be understood that sometimesapplicants are referring to the polymers by the monomers used to makethem or the amounts of the monomers used to make them. While such adescription may not include the specific nomenclature used to describethe final polymer or may not contain product-by-process terminology, anysuch reference to monomers and amounts should be interpreted to meanthat the polymer is made from those monomers or that amount of themonomers, and the corresponding polymers and compositions thereof.

The materials, methods, and examples herein are illustrative only and,except as specifically stated, are not intended to be limiting.

As used herein, the terms “comprises,” “comprising,” “includes,”“including,” “has,” “having” or any other variation thereof, areintended to cover a non-exclusive inclusion. For example, a method,process, article, or apparatus that comprises a list of elements is notnecessarily limited only those elements but may include other elementsnot expressly listed or inherent to such method, process, article, orapparatus. Further, unless expressly stated to the contrary, “or” refersto an inclusive or and not to an exclusive or. For example, a conditionA or B is satisfied by any one of the following: A is true (or present)and B is false (or not present), A is false (or not present) and B istrue (or present), and both A and B are true (or present).

Also, use of the “a” or “an” are employed to describe elements andcomponents of the invention. This is done merely for convenience and togive a general sense of the invention. This description should be readto include one or at least one and the singular also includes the pluralunless it is obvious that it is meant otherwise.

It will be understood that although the terms first, second, third, etc.may be used herein to describe various elements, components, regions,layers and/or sections, these elements, components, regions, layers,and/or sections should not be limited by these terms. These terms areonly used to distinguish one element, component, region, layer and/orsection from another element, component, region, layer and/or section.Thus, a first element, component, region, layer and/or section could betermed a second element, component, region, layer and/or section withoutdeparting from the teachings of the present invention. Similarly, theterms “top” and “bottom” are only relative to each other. It will beappreciated that when an element, component, layer or the like isinverted, what is the “bottom” before being inverted would be the “top”after being inverted, and vice versa. When an element is referred to asbeing “on” or “disposed on” another element, it means positioning on orbelow the object portion, but does not essentially mean positioning onthe upper side of the object portion based on a gravity direction, andit can be directly on the other element or intervening elements may bepresent therebetween. In contrast, when an element is referred to asbeing “directly on” or “disposed directly on” another element, there areno intervening elements present.

Further, it will also be understood that when one element, component,region, layer and/or section is referred to as being “between” twoelements, components, regions, layers and/or sections, it can be theonly element, component, region, layer and/or section between the twoelements, components, regions, layers and/or sections, or one or moreintervening elements, components, regions, layers and/or sections mayalso be present.

Organic Solvents

Useful organic solvents for the synthesis of the polymers of the presentinvention are preferably capable of dissolving the polymer precursormaterials. Such a solvent should also have a relatively low boilingpoint, such as below 225° C., so the polymer can be dried at moderate(i.e., more convenient and less costly) temperatures. A boiling point ofless than 210, 205, 200, 195, 190, or 180° C. is preferred.

Useful organic solvents include: N-methylpyrrolidone (NMP),N,N-dimethylacetamide (DMAc), methyl ethyl ketone (MEK),N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), tetramethyl urea(TMU), glycol ethyl ether, diethyleneglycol diethyl ether,1,2-dimethoxyethane (monoglyme), diethylene glycol dimethyl ether(diglyme), 1,2-bis-(2-methoxyethoxy) ethane (triglyme),gamma-butyrolactone, and bis-(2-methoxyethyl) ether, tetrahydrofuran(THF), ethyl acetate, hydroxyethyl acetate glycol monoacetate, acetoneand mixtures thereof. In one embodiment, preferred solvents includeN-methylpyrrolidone (NMP) and N,N-dimethylacetamide (DMAc).

Diamines

In one embodiment, any number of suitable diamines can be used formonomers to form polymer backbone compositions comprising an imidegroup. Some monomers may be preferred for thermoset polymercompositions, while others may be preferred in thermoplastic polymercompositions. As used herein when describing polymer compositionscomprising an imide group, the term “thermoplastic” is intended todescribe a polymer which, when heated above room temperature, will reachits softening temperature before decomposing, and the term “thermoset”is intended to describe a polymer which, when heated above roomtemperature, will decompose before reaching its softening temperature.Thus, when describing polymer compositions comprising an imide group,“thermoset polymers” are not necessarily crosslinked as in thetraditional definition of thermoset polymers.

In one embodiment, a suitable diamine for forming the polymer backbonecan include an aliphatic diamine, such as 1,2-diaminoethane,1,6-diaminohexane (HMD), 1,4-diaminobutane, 1,5 diaminopentane,1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane,1,10-diaminodecane (DMD), 1,11-diaminoundecane, 1,12-diaminododecane(DDD), 1,16-hexadecamethylenediamine,1,3-bis(3-aminopropyl)-tetramethyldisiloxane,trans-1,4-diaminocyclohexane (CHDA), isophoronediamine (IPDA),bicyclo[2.2.2]octane-1,4-diamine and combinations thereof. Otheraliphatic diamines suitable for practicing the invention include thosehaving six to twelve carbon atoms or a combination of longer chain andshorter chain diamines so long as both flexibility of the polymer aremaintained. Long chain aliphatic diamines may increase flexibility.

In one embodiment, a suitable diamine for forming the polymer backbonecan include an alicyclic diamine (can be fully or partially saturated),such as a cyclobutane diamine (e.g., cis- andtrans-1,3-diaminocyclobutane, 6-amino-3-azaspiro[3.3]heptane, and3,6-diaminospiro[3.3]heptane), bicyclo[2.2.1]heptane-1,4-diamine,isophoronediamine, and bicyclo[2.2.2]octane-1,4 diamine. Other alicyclicdiamines can include cis-1,4 cyclohexane diamine, trans-1,4 cyclohexanediamine, 1,4-bis(am inomethyl)cyclohexane,4,4′-methylenebis(cyclohexylamine),4,4′-methylenebis(2-methyl-cyclohexylamine), bis(aminomethyl)norbornane.

In one embodiment, a suitable diamine for forming the polymer backbonecan include a fluorinated aromatic diamine, such as2,2′-bis(trifluoromethyl) benzidine (TFMB),trifluoromethyl-2,4-diaminobenzene, trifluoromethyl-3,5-diaminobenzene,2,2′-bis-(4-aminophenyl)-hexafluoro propane,4,4′-diamino-2,2′-trifluoromethyl diphenyloxide,3,3′-diamino-5,5′-trifluoromethyl diphenyloxide,9.9′-bis(4-aminophenyl)fluorene,4,4′-trifluoromethyl-2,2′-diaminobiphenyl,4,4′-oxy-bis-[2-trifluoromethyl)benzene amine] (1,2,4-OBABTF),4,4′-oxy-bis-[3-trifluoromethyl)benzene amine],4,4′-thio-bis-[(2-trifluoromethyl)benzene-amine],4,4′-thiobis[(3-trifluoromethyl)benzene amine],4,4′-sulfoxyl-bis-[(2-trifluoromethyl)benzene amine,4,4′-sulfoxyl-bis-[(3-trifluoromethyl)benzene amine],4,4′-keto-bis-[(2-trifluoromethyl)benzene amine],1,1-bis[4′-(4″-amino-2″-trifluoromethylphenoxy)phenyl]cyclopentane,1,1-bis[4′-(4″-amino-2″-trifluoromethylphenoxy)phenyl]cyclohexane,2-trifluoromethyl-4,4′-diaminodiphenyl ether;1,4-(2′-trifluoromethyl-4′,4″-diaminodiphenoxy)-benzene,1,4-bis(4′-aminophenoxy)-2-[(3′,5′-ditrifluoromethyl)phenyl]benzene,1,4-bis[2′-cyano-3′(″4-aminophenoxy)phenoxy]-2-[(3′,5-ditrifluoro-methyl)phenyl]benzene(6FC-diamine),3,5-diamino-4-methyl-2′,3′,5′,6′-tetrafluoro-4′-tri-fluoromethyldiphenyloxide,2,2-Bis[4′(4”-aminophenoxy)phenyl]phthalein-3′,5-bis(trifluoromethyl)anilide(6FADAP) and 3,3′,5,5′-tetrafluoro-4,4′-diamino-diphenylmethane (TFDAM).

Other useful diamines for forming the polymer backbone can includep-phenylenediamine (PPD), m-phenylenediamine (MPD),2,5-dimethyl-1,4-diaminobenzene, 2,5-dimethyl-1,4-phenylenediamine(DPX), 2,2-bis-(4-aminophenyl) propane,1,4-naphthalenediamine,1,5-naphthalenediamine, 4,4′-diaminobiphenyl,4,4″-diamino terphenyl, 4,4′-diamino benzanilide, 4,4′-diaminophenylbenzoate, 4,4′-diaminobenzophenone, 4,4′-diaminodiphenylmethane (MDA),4,4′-diaminodiphenyl sulfide, 4,4′-diaminodiphenyl sulfone,3,3′-diaminodiphenyl sulfone, bis-(4-(4-aminophenoxy)phenyl sulfone(BAPS), 4,4′-bis-(aminophenoxy)biphenyl (BAPB), 4,4′-diaminodiphenylether (ODA), 3,4′-diaminodiphenyl ether, 4,4′-diaminobenzophenone,4,4′-isopropylidenedianiline, 2,2′-bis-(3-aminophenyl)propane,N,N-bis-(4-aminophenyl)-n-butylamine, N,N-bis-(4-aminophenyl)methylamine, 1,5-diaminonaphthalene, 3,3′-dimethyl-4,4′-diaminobiphenyl,m-amino benzoyl-p-amino anilide, 4-aminophenyl-3-aminobenzoate, N,N-bis-(4-aminophenyl) aniline, 2,4-diaminotoluene, 2,5-diaminotoluene,2,6-diaminotoluene, 2,4-diamine-5-chlorotoluene,2,4-diamine-6-chlorotoluene, 2,4-bis-(beta-amino-t-butyl) toluene,bis-(p-beta-amino-t-butyl phenyl) ether,p-bis-2-(2-methyl-4-aminopentyl) benzene, m-xylylene diamine, andp-xylylene diamine.

Other useful diamines for forming the polymer backbone can include1,2-bis-(4-aminophenoxy)benzene, 1,3-bis-(4-aminophenoxy) benzene(RODA), 1,2-bis-(3-aminophenoxy)benzene, 1,3-bis-(3-aminophenoxy)benzene, 1-(4-aminophenoxy)-3-(3-aminophenoxy) benzene,1,4-bis-(4-aminophenoxy) benzene, 1,4-bis-(3-aminophenoxy) benzene,1-(4-aminophenoxy)-4-(3-aminophenoxy) benzene,2,2-bis-(4-[4-aminophenoxy]phenyl) propane (BAPP), 2,2′-bis-(4-phenoxyaniline) isopropylidene, 2,4,6-trimethyl-1,3-diaminobenzene and2,4,6-trimethyl-1,3-diaminobenzene.

Dianhydrides

In one embodiment, any number of suitable dianhydrides can be used formonomers to form the polymer backbone. Some monomers may be preferredfor thermoset polymer layers, while others may be preferred inthermoplastic polymer layers. The dianhydrides can be used in theirtetra-acid form (or as mono, di, tri, or tetra esters of the tetraacid), or as their diester acid halides (chlorides). However, in someembodiments, the dianhydride form can be preferred, because it isgenerally more reactive than the acid or the ester.

Examples of suitable dianhydrides include3,3′,4,4′-biphenyltetracarboxylic dianhydride (BPDA),1,2,5,6-naphthalene tetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalene tetracarboxylicdianhydride, 2-(3′,4′-dicarboxyphenyl) 5,6-dicarboxybenzimidazoledianhydride, 2-(3′,4′-dicarboxyphenyl) 5,6-dicarboxybenzoxazoledianhydride, 2-(3′,4′-dicarboxyphenyl) 5,6-dicarboxybenzothiazoledianhydride, 2,2′,3,3′-benzophenone tetracarboxylic dianhydride,2,3,3′,4′-benzophenone tetracarboxylic dianhydride,3,3′,4,4′-benzophenone tetracarboxylic dianhydride (BTDA),2,2′,3,3′-biphenyltetracarboxylic dianhydride,2,3,3′,4′-biphenyltetracarboxylic dianhydride,bicyclo-[2,2,2]-octen-(7)-2,3,5,6-tetracarboxylic-2,3,5,6-dianhydride,4,4′-thio-diphthalic anhydride, bis (3,4-dicarboxyphenyl) sulfonedianhydride, bis (3,4-dicarboxyphenyl) sulfoxide dianhydride (DSDA), bis(3,4-dicarboxyphenyl oxadiazole-1,3,4) p-phenylene dianhydride, bis(3,4-dicarboxyphenyl) 2,5-oxadiazole 1,3,4-dianhydride, bis2,5-(3′,4′-dicarboxydiphenylether) 1,3,4-oxadiazole dianhydride,4,4′-oxydiphthalic anhydride (ODPA), bis (3,4-dicarboxyphenyl) thioether dianhydride, bisphenol A dianhydride (BPADA), bisphenol Sdianhydride, bis-1,3-isobenzofurandione, 1,4-bis(4,4′-oxyphthalicanhydride) benzene, bis (3,4-dicarboxyphenyl) methane dianhydride,cyclopentadienyl tetracarboxylic dianhydride, ethylene tetracarboxylicdianhydride, perylene 3,4,9,10-tetracarboxylic dianhydride, pyromelliticdianhydride (PMDA), tetrahydrofuran tetracarboxylic dianhydride,1,3-bis-(4,4′-oxydiphthalic anhydride) benzene,2,2-bis(3,4-dicarboxyphenyl)propane dianhydride,2,6-dichloronaphthalene-1,4,5,8-tetracarboxylic dianhydride,2,7-dichloronaphthalene-1,4,5,8-tetracarboxylic dianhydride,2,3,6,7-tetrachloronaphthalene-1,4,5,8-tetracarboxylic dianhydride,phenanthrene-1,8,9,10-tetracarboxylic dianhydride,pyrazine-2,3,5,6-tetracarboxylic dianhydride,benzene-1,2,3,4-tetracarboxylic dianhydride andthiophene-2,3,4,5-tetracarboxylic dianhydride.

In one embodiment, a suitable dianhydride can include an alicyclicdianhydride, such as cyclobutane-1,2,3,4-tetracarboxylic diandydride(CBDA), 1,2,4,5-cyclohexanetetracarboxylic dianhydride,1,2,3,4-cyclohexanetetracarboxylic dianhydride,1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride,1,2,3,4-cyclopentanetetracarboxylic dianhydride (CPDA),hexahydro-4,8-ethano-1H,3H-benzo[1,2-c:4,5-c′]difuran-1,3,5,7-tetrone(BODA), 3-(carboxymethyl)-1,2,4-cyclopentanetricarboxylic1,4:2,3-dianhydride (TCA), and meso-butane-1,2,3,4-tetracarboxylicdianhydride. In one embodiment, an alicyclic dianhydride can be presentin an amount of about 70 mole percent or less, based on the totaldianhydride content of the polymer.

In one embodiment, a suitable dianhydride for forming the polymerbackbone can include a fluorinated dianhydride, such as4,4′-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) and 9,9-bis(trifuoromethyl)-2,3,6,7-xanthene tetracarboxylic dianhydride.

In one embodiment, poly(amide-imides) can be produced from acylchloride-containing monomers such as terephthaloyl chloride (TPCl),isophthaloyl chloride (IPCl), biphenyl dicarbonyl chloride (BPCI),naphthalene dicarbonyl chloride, terphenyl dicarbonyl chloride,2-fluoro-terephthaloyl chloride and trimellitic anhydride.

In one embodiment, poly(ester-imides) can be produced from polyols whichcan react with carboxylic acid or the ester acid halides to generateester linkages.

The dihydric alcohol component may be almost any alcoholic diolcontaining two esterifiable hydroxyl groups. Mixtures of suitable diolsmay also be included. Suitable diols for use herein include for example,ethylene glycol, propylene glycol, 1,4-butane diol, 1,5-pentane diol,neopenty glycol, etc.

The polyhydric alcohol component may be almost any polyhydric alcoholcontaining at least 3 esterifiable hydroxyl groups. In one embodiment,mixtures of polyhydric alcohols may be employed. Suitable polyhydricalcohols include, for example, tris(2-hydroxyethyl) isocyanurate,glycerine, 1,1,1-trimethylolethane, 1,1,1-trimethylolpropane, and theirmixtures.

In some cases, useful diamine and dianhydride monomers contain estergroups. Examples of these monomers are diamines such as 4-aminophenyl4-aminobenzoate, 4-amino-3-methylphenyl-4-aminobenzoate and dianhydridessuch as p-phenylene bis(trimellitate) dianhydride.

In some cases, useful diamine and dianhydride monomers contain amidegroups. Examples of these monomers are diamines such as 4,4′-diaminobenzamide (DABAN), and dianhydrides such asN,N′-(2,2′-Bis(trifluoromethyl)-[1,1′-biphenyl]-4,4′-diyl)bis(1,3-dioxo-1,3-dihydroisobenzofuran-5-carboxamide)andN,N′-(9H-Fluoren-9-ylidenedi-4,1-phenylene)bis[1,3-dihydro-1,3-dioxo-5-isobenzofurancarboxamide].

Higher order copolymers having an imide group can include any of themonomers described above.

Amine Reagents

In one embodiment, an amine reagent, such as a primary or secondaryamine, can be used to adhere a polymer layer having a polymer with animide group to an inorganic substrate. While not being bound to anytheory, it is believed that the amine reagent reacts with the imide tocreate a covalent bond to the imide-containing polymer by creating anamide bond. Previous references of crosslinking reactions indicate thischemistry is facile and can occur at room temperature with primary orsecondary amine crosslinking agents (see, for example, Y. Liu et al, JMembr Sci 189 (2001), pp. 231-239).

In one embodiment, an alkoxide-containing amine reagent can also beused, which can directly interact with inorganic surfaces by theinteraction of the alkoxide with —SiOH groups. In addition, the aminegroups can interact with inorganic surfaces and the —SiOH groups presenton the surface to help improve adhesion.

In one embodiment, the imide-containing polymer can have a range ofglass transition temperatures (T_(g)'s). Typically, the laminationconditions (heat and applied pressure) will be, as a lower limit, closeto the glass transition temperature of the polymer film layer. In oneembodiment, a polymer film layer can have a T_(g) of about 300° C. orless. In one embodiment, lamination is carried out at a temperature in arange of from about 20 degrees below to about 50 degrees above the T_(g)of the polymer film layer. For amorphous or semi-crystalline polymers,T_(g) can be affected by several parameters. An increase in molecularweight leads to a decrease in chain end concentration resulting in adecreased free volume at the end group region and increase in T_(g). Theinsertion of rigid or inflexible groups in the chain or bulky andinflexible side or pendant groups will increase the T_(g) of the polymerdue to a decrease in chain mobility. Conversely, imide-containingpolymers which contain monomers which are flexible and possess manydegrees of freedom will lower T_(g). For these imide-containingpolymers, aliphatic imide diamines such as n-alkyl diamines willincrease chain mobility, increase free volume (volume not occupied bythe polymer) and lower T_(g). Likewise, an increase in crosslinkingdecreases chain mobility, leading to a decrease in free volume andincrease in T_(g). In addition, the presence of polar groups increasesintermolecular forces, inter-chain attraction and cohesion, leading to adecrease in free volume resulting in an increase in T_(g).

In one embodiment, the amines that can be derived from metal alkoxidescontain at least one primary or secondary amine; the metal atom can be,for instance, silicon, titanium, aluminum, zirconium, niobium ortantalum. In one embodiment, mixtures of alkoxides and metal alkoxideclusters containing more than one metal cation can also be used. In oneembodiment, metal alkoxides containing a primary amine, such asamine-containing alkoxysilanes, can be pre-hydrolyzed to produceamine-containing oligomers, essentially amplifying the number of aminesat the interface.

In one embodiment, at least one of a hydrolysis and condensation productof the amine precursor, if it contains an alkoxide group, can be used.As used herein, a “hydrolysis product” or a “hydrosylate” refers to analkoxide in which at least one of the alkoxide substituents have beenreplaced by a hydroxyl group. For example, in the case of alkoxysilanes,condensates can form when two hydroxyl groups attached to Si condense toform direct Si—O—Si linkages. In this way, alkoxysilane oligomers canform.

In one embodiment, a hydrosylate and/or condensate can be formed bycontacting the amine-containing alkoxide with water. In one embodiment,a hydrosylate and/or condensate can be formed by contacting theamine-containing alkoxide with from about 1 to about 200 moles of waterper mole of hydrolyzable functional group bonded to the silicon of theoxysilane.

In one embodiment, hydrosylate and/or condensate can be formed bycontacting the oxysilane with water in the presence of a lower alkylalcohol solvent. Representative lower alkyl alcohol solvents includealiphatic and alicyclic C1-C5 alcohols such as methanol, ethanol,n-propanol, iso-propanol and cyclopentanol. In one embodiment, the loweralkyl alcohol solvent is ethanol or methanol.

In one embodiment, hydrolysate and/or condensate can be formed bycontacting the oxysilane with water in the presence of an organic acidthat catalyzes hydrolysis of one or more alkoxide substituents andfurther may catalyze condensation of the resultant hydrosylates. Theorganic acids catalyze hydrolysis of alkoxide substituents, such asalkoxy and aryloxy, and result in the formation of hydroxyl (silanol)groups in their place. Organic acids comprise the elements carbon,oxygen and hydrogen, optionally nitrogen and sulfur, and contain atleast one labile (acidic) proton. Examples of organic acids includecarboxylic acids such as acetic acid, maleic acid, oxalic acid, andformic acid, as well as sulfonic acids such as methanesulfonic acid andtoluene sulfonic acid. In one embodiment, the organic acids can have apK_(a) of at least about 4.7. In one embodiment an organic acid isacetic acid.

In some embodiments, polyamine oligomers such as polyetheramines (e.g.Jeffamine® products from Huntsman Corp., The Woodlands, Tex.) and otherpolyamine monomers (e.g. 1,3,5-tris(4-aminophenoxy)benzene) can be used.These reagents are polyamine oligomers that can interact with thepolymer film layer surface and with —SiOH and other functional groups onthe inorganic substrate surface.

Polyamine siloxanes can also be used to promote adhesion betweenimide-containing polymer layers and inorganic substrates. Examplesinclude various silamines which are amino-functionalized siloxanes andsilicones. Examples includepoly[(1,3-(N,N-dimethylamino)-2-propoxy)siloxane],poly[(methyl-3-amino-1-propoxy)siloxane],poly[(1,3-(N,N-dimethylamino)-2-propoxy)siloxane],bis(trimethylsiloxy)-1,3-dimethyl-1,3-(N,N-(1′,e′-dimethylamino)-2′-propoxy)siloxane.

Glass-Transition Temperature Reducing Compounds

In one embodiment, glass-transition (T_(g)) reducing compounds are usedin polymer compositions for shaped bodies and coating solutions thatform polymer films. These T_(g) reducing compounds can have an aminemoiety that can be an amine or a masked amine that can be converted toan amine, wherein the masked amine can be chemically converted,thermally converted, photo-converted or dissociated. In someembodiments, an amine can be useful as both an amine reagent and a T_(g)reducing compound. In one embodiment, amine T_(g) reducing compoundscontaining one primary amine can be used. These can include reagentssuch as compounds containing aliphatic reagents with at least oneprimary amine, aromatic-containing reagents containing at least oneprimary amine and olefinic reagents containing at least one primaryamine. Examples include phenyl ethyl amine, 2-(2-aminoethyl)pyridine,1-aminoheptane. In one embodiment, monoamine polyetheramines can beused, such as, for example, Jeffamine® M600 and Jeffamine® M2005. Insome embodiments, amino-functionalized polysiloxanes can be used (e.g.aminoethylaminopropyl poly(dimethylsiloxane)). In one embodiment, thestructure of the amine comprises an oligomer or polymer chain and theamine has a molecular weight of 5,000 g/mol or less, 2,500 g/mol orless, or 1,000 g/mol or less. In some embodiments, the structure of theamine is free of an oligomer or polymer chain repeat unit and has amolecular weight of 500 g/mol or less, 400 g/mol or less, or 300 g/molor less.

In one embodiment, amine T_(g) reducing compounds can include polyaminespolyetheramines, such as Jeffamine® D-230, Jeffamine® D-400, Jeffamine®D-2000, Jeffamine® D-2010, Jeffamine® D-4000, Jeffamine® ED-600,Jeffamine® ED-900, Jeffamine® D-2003, Jeffamine® EDR-148, Jeffamine®THF-100, Jeffamine® THF-170, Jeffamine® SD-2001, Jeffamine® D-205 andJeffamine® RFD-270.

In one embodiment, amine T_(g) reducing compounds can include aromaticprimary diamines, such as m-xylylene diamine, and p-xylylene diamine.

In one embodiment, amine T_(g) reducing compounds can include aliphaticprimary diamines, such as 1,2-diaminoethane, 1,6-diaminohexane,1,4-diaminobutane, 1,7-diaminoheptane, 1,8-diaminooctane,1,9-diaminononane, 1,10-diaminodecane (DMD), 1,11-diaminoundecane,1,12-diaminododecane (DDD), 1,16-hexadecamethylenediamine,1,3-bis(3-aminopropyl)-tetramethyldisiloxane, isophoronediamine,bicyclo[2.2.2]octane-1,4-diamine and combinations thereof. Otheraliphatic diamines suitable for practicing the invention include thosehaving six to twelve carbon atoms or a combination of longer chain andshorter chain diamines or cycloaliphatic diamines.

In one embodiment, amine T_(g) reducing compounds can include secondaryamines, such as piperazine, N,N′-diisopropylethylenediamine,N,N′-diisopropyl-1,3-propanediamine andN,N′-dimethyl-1,3-propanediamine, and triamines, such as2,4,6-triaminopyrimidine (TAP), melamine, diethylenetriamine, Jeffamine®T-403, Jeffamine® T-3000, Jeffamine® T-5000. In addition, many diaminesthat may be used as a diamine monomer for polymers, as described above,may also be useful as T_(g) reducing compounds.

In one embodiment, a T_(g) reducing compound can contain alkyl chains asmasking groups, such as N-alkyl or N,N-dialkyl chains, for example,methyl and tert-butyl chains. In one embodiment, a T_(g) reducingcompound can contain an aromatic masking group, such as N-aryl andN,N-diaryl groups. In one embodiment, a T_(g) reducing compound can be acompound that contains a benzyl masking group. In one embodiment a T_(g)reducing compound can be a compound that contains a silyl derivative asthe masking group, such as tert-butyldiphenylsilyl. Many functionalgroups can act as masking groups for amines towards soluble polymershaving an imide group. See, for example, P. G. M. Wuts and T. W. Greene,Greene's Protective Groups in Organic Synthesis, 4th Ed., John Wiley &Sons, Inc. (2007) (“Greene's”).

In one embodiment, a T_(g) reducing compound can contain carbamatemasking groups. Carbamates can be converted to form amines by a varietyof methods. Many carbamates can be converted to form amines through theapplication of heat at temperatures typically greater than 150° C. Avariety of chemical routes can also be used to convert a carbamatefunctional group to form a reactive amine. For example, the introductionof a base, such as tert-butyl alcohol, or an acid, such as phosphoricacid or trifluoroacetic acid, can be used to convert the carbamate toform a reactive amine. Photo-induced reactions can also be used tocleave carbamates to form reactive amines. A variety of methods ofconverting a range of carbamates are described in Greene's. In oneembodiment, a T_(g) reducing compound can be a compound that containscarbamate masking groups that are thermally cleavable, such astert-butyloxycarbonyl, fluorenylmethoxycarbonyl, and benzyl carbamate,or photo-cleavable, such as 3,5-dimethoxybenzyl carbamate, m-nitrophenylcarbamate, and o-nitrobenzyl carbamate.

In one embodiment, a T_(g) reducing compound can contain an amidemasking group that can be cleaved to form an amine through theintroduction of a different chemical species. For example, the differentchemical species can include a base such as sodium or potassiumhydroxide, ammonia, or a tertiary amine. In other instances, acids suchas hydrochloric acid, or enzymes such as penicillin acylase orα-chymotrypsin can be used to cleave the amide to form a reactive amine.

In one embodiment, a T_(g) reducing compound containing an amide maskinggroup can be photo-cleaved, such as by irradiating with 245 nm light, orthermally cleaved at temperatures of greater than 65° C. A broad rangeof amides, such as those described in Greene's, can be used as T_(g)reducing compounds. In one embodiment, a T_(g) reducing compound can bea compound that contains an amide masking group, such as acetamide,trifluoroacetamide, formamide, sulfonamide, such asp-toluenesulfonamide, trichloroacetamide, chloroacetamide,phenylacetamide, 3-phenylpropanamide, 3-pyridylcarboxamide,N-benzoylphenylalanyl, and benzamide.

In one embodiment, a T_(g) reducing compound can be an ammonium saltmade from an acid such as acetic acid, butyric acid, pivalic acid,hydrochloric acid or sulfuric acid. An ammonium salt which can be usedto mask an amine in the T_(g) reducing compound can be formed by theaddition of organic and/or mineral Brønsted acids. The direct reactionof the acid and the T_(g) reducing compound, containing an amine, willform the ammonium salt. The ammonium salt can be dissociated by theapplication of heat. The kinetic inhibition is also controlled by theacid-ammonium equilibrium constant. If there is not sufficient acid insolution, as determined by the acid-ammonium equilibrium constant, theammonium salt can be dissociated to form an amine in the T_(g) reducingcompound. In one embodiment, an ammonium salt can be made from thereaction of the amine with acetic acid or trifluoroacetic acid, and thendissociated with heat.

In one embodiment, the T_(g) reducing compound is selected from a singlemulti-functional compound, a combination of multiple single-functionalcompounds, or a mixture thereof.

In one embodiment, a first polymer derived from a soluble polymercomposition having a T_(g) reducing compound having an amine group has aT_(g) that is lower than a second polymer derived from the same solublepolymer composition, but without a T_(g) reducing compound having anamine group. In one embodiment, the second polymer has a T_(g) of 300°C. or less, 275° C. or less, 250° C. or less, 225° C. or less, 200° C.or less, or 180° C. or less. In one embodiment, the difference betweenthe T_(g)'s of the first and second polymers is 5 degrees or more, 10degrees or more, 15 degrees or more, 20 degrees or more, 30 degrees ormore, 40 degrees or more, or 50 degrees or more.

In one embodiment, the T_(g) reducing compound is present in the polymercomposition in an amount in the range of from 0.01 to 90 mol %, or from5 to 80 mol %, or from 5 to 40 mol % based on the total moles of solublepolymer and T_(g) reducing compound in the composition. For example, apolymer composition with 30 mol % of the T_(g) reducing compound willhave 70 mol % of the soluble polymer.

Polymer Compositions

In one embodiment, a polymer composition containing a polymer having animide group can be produced by combining a diamine and a dianhydride(monomer or other polyimide precursor form) together with a solvent toform a polyamic acid (also called a polyamide acid) solution. Thedianhydride and diamine can be combined in a molar ratio of about 0.90to 1.10. The molecular weight of the polyamic acid formed therefrom canbe adjusted by adjusting the molar ratio of the dianhydride and diamine.

In one embodiment, for a shaped body, a powdered resin of a polymerderived from a soluble polymer composition can be blended with a T_(g)reducing compound having an amine group and shaped using direct formingor hot compression molding processes. Other possible processes include,for example, hot coining or ram extrusion. The soluble polymercomposition may be partially or fully imidized and can be prepared asdescribed below for films. In one embodiment, the soluble polymercomposition may be substantially imidized, as described below. In oneembodiment, a pressing powder can further include any one of a number ofadditives, such as processing aids (e.g., oligomers), antioxidants,light stabilizers, flame retardant additives, anti-static agents, heatstabilizers, ultraviolet absorbing agents, inorganic fillers or variousreinforcing agents, such as those additives described below for polymerfilms.

In one embodiment, a pressing is first formed by pressing the blendedpowder at compressive pressures in a range of from 10 to 1000 MPa, at atemperature between 0 and 100° C. In one embodiment, the pressings(green parts) obtained have a density of 1.20 g/ml or more. In oneembodiment the pressings have a density in the range of from 1.25 to 1.5or from 1.25 to 1.4 g/ml. In one embodiment, the pressings are thensintered in an air or protective gas atmosphere, for example nitrogen,at a temperature in a range of from about 20 degrees below to about 50degrees above the T_(g) of the soluble polymer composition for 0.1 to 10hours. Typically, the highest temperature achieved during the pressingprocess is not less than 20° C. below the T_(g) of the soluble polymercomposition. Higher temperatures can be used for pressing, but attemperatures greater than 50° C. above the T_(g) of the polymer, somediscoloration of the polymer can occur, which may be undesirable in theapplications that require good optical properties, such as transparencyand low color. Hence, higher temperature pressing may require shorterresidence times. In one embodiment, the parts are heated in thesintering oven with a ramp of 0.1 to 5° C./min up to the final sinteringtemperature. In one embodiment, a polymer composition for a shaped bodycan have a T_(g) of about 300° C. or less.

In one embodiment, for shaped bodies, a hot compression molding processcan be used. A shaped body is produced by pressing the blended powder atpressures of 100 to 1000 bar and a temperatures in a range of from about20 degrees below to about 50 degrees above the T_(g) of the polymercomposition until sintering is complete.

In one embodiment, for a film, a polyamic acid casting solution isderived from the polyamic acid solution. The polyamic acid castingsolution, and/or the polyamic acid solution, can optionally be combinedwith conversion chemicals like: (i) one or more dehydrating agents, suchas, aliphatic acid anhydrides (acetic anhydride, etc.) and/or aromaticacid anhydrides; and (ii) one or more catalysts, such as, aliphatictertiary amines (triethyl amine, etc.), aromatic tertiary amines(dimethyl aniline, etc.) and heterocyclic tertiary amines (pyridine,picoline, isoquinoline, etc.). The anhydride dehydrating material it isoften used in molar excess compared to the amount of amide acid groupsin the polyamic acid. The amount of acetic anhydride used is typicallyabout 2.0-4.0 moles per equivalent (repeat unit) of polyamic acid.Generally, a comparable amount of tertiary amine catalyst is used.Nanoparticles, dispersed or suspended in solvent as described above, arethen added to the polyamic acid solution.

In one embodiment, a conversion chemical can be an imidization catalyst(sometimes called an “imidization accelerator”) that can help lower theimidization temperature and shorten the imidization time. Typicalimidization catalysts can range from bases such as imidazole,1-methylimidazole, 2-methylimidazole, 1,2-dimethylimidazole,2-phenylimidazole, benzimidazole, isoquinoline, substituted pyridinessuch as methyl pyridines, lutidine, and trialkylamines and hydroxy acidssuch as isomers of hydroxybenzoic acid. The ratio of these catalysts andtheir concentration in the polyamic acid layer will influenceimidization kinetics and the film properties.

In one embodiment, the polyamic acid solution, and/or the polyamic acidcasting solution, is dissolved in an organic solvent at a concentrationfrom about 5.0 or 10% to about 15, 20, 25, 30, 35 or 40% by weight.

The solvated mixture (the polyamic acid casting solution) can then becast or applied onto a support, such as an endless belt or rotatingdrum, to give a film. Alternatively, it can be cast on a polymericcarrier such as PET, other forms of Kapton® polyimide film (e.g.,Kapton® HN or Kapton OL films) or other polymeric carriers. Next, thesolvent-containing film can be converted into a self-supporting film byheating at an appropriate temperature (thermal curing). The film canthen be separated from the support, oriented such as by tentering, withcontinued heating (drying and curing) to provide a polymer film.

Useful methods for producing polymer films containing a polyimide can befound in U.S. Pat. Nos. 5,166,308 and 5,298,331, which are incorporateby reference into this specification for all teachings therein. Numerousvariations are also possible, such as,

-   -   (a) A method wherein the diamine components and dianhydride        components are preliminarily mixed together and then the mixture        is added in portions to a solvent while stirring.    -   (b) A method wherein a solvent is added to a stirring mixture of        diamine and dianhydride components. (contrary to (a) above)    -   (c) A method wherein diamines are exclusively dissolved in a        solvent and then dianhydrides are added thereto at such a ratio        as allowing to control the reaction rate.    -   (d) A method wherein the dianhydride components are exclusively        dissolved in a solvent and then amine components are added        thereto at such a ratio to allow control of the reaction rate.    -   (e) A method wherein the diamine components and the dianhydride        components are separately dissolved in solvents and then these        solutions are mixed in a reactor.    -   (f) A method wherein the polyamic acid with excessive amine        component and another polyamic acid with excessive dianhydride        component are preliminarily formed and then reacted with each        other in a reactor, particularly in such a way as to create a        non-random or block copolymer.    -   (g) A method wherein a specific portion of the amine components        and the dianhydride components are first reacted and then the        residual diamine components are reacted, or vice versa.    -   (h) A method wherein the conversion chemicals (catalysts) are        mixed with the polyamic acid to form a polyamic acid casting        solution and then cast to form a gel film.    -   (i) A method wherein the components are added in part or in        whole in any order to either part or whole of the solvent, also        where part or all of any component can be added as a solution in        part or all of the solvent.    -   (j) A method of first reacting one of the dianhydride components        with one of the diamine components giving a first polyamic acid.        Then reacting another dianhydride component with another amine        component to give a second polyamic acid. Then combining the        amic acids in any one of a number of ways prior to film        formation.

In one embodiment, the polyamic acid solution can be heated, optionallyin the presence of an imidization catalyst, to partially or fullyimidize the polyamic acid, converting it to a polymer having an imidegroup. Temperature, time, and the concentration and choice ofimidization catalyst can impact the degree of imidization of thepolyamic acid solution. Preferably, the solution should be substantiallyimidized. In one embodiment, for a substantially imidized polymersolution, greater than 85%, greater than 90%, or greater than 95% of theamic acid groups are converted to the polymer having an imide group, asdetermined by infrared spectroscopy.

In one embodiment, the solvated mixture (the substantially imidizedsolution) can be cast to form a polymer film. In another embodiment, thesolvated mixture (the first substantially imidized solution) can beprecipitated with an antisolvent, such as water or alcohols (e.g.,methanol, ethanol, isopropyl alcohol), and the solid substantiallyimidized polymer resin can be isolated. In one embodiment, for asubstantially imidized polymer resin, greater than 85%, greater than90%, or greater than 95% of the amic acid groups are converted to thepolymer having an imide group, as determined by infrared spectroscopy.For instance, isolation can be achieved through filtration, decantation,centrifugation and decantation of the supernatant liquid, distillationor solvent removal in the vapor phase, or by other known methods forisolating a solid precipitate from a slurry. In one embodiment, theprecipitate can be washed to remove the catalyst. After washing, theprecipitate may be substantially dried, but need not be completely dry.The polymer precipitate can be re-dissolved in a second solvent, such asmethyl isobutyl ketone (MIBK), methyl ethyl ketone (MEK), ethyl acetate,methyl acetate, ethyl formate, methyl formate, tetrahydrofuran, acetone,DMAc, NMP and mixtures thereof, to form a second substantially imidizedsolution (a casting solution), which can be cast to form a polymer film.

In one embodiment, a substantially polymerized solution is formed usingmonomers (diamines or dianhydrides) with structural characteristicsimportant for solubility, including flexible linkages, such as, but notlimited to, aliphatic spacers, ethers, thioethers, substituted amines,amides, esters, and ketones, weak intermolecular interactions, bulkysubstitutions, non-coplanarity, non-linearity and asymmetry. Examples ofdiamines that incorporate some of these characteristics are aliphaticdiamines, such as HMD, CHDA and IPDA, and aromatic diamines, such as MTBTFMB, MPD, RODA, BAPP, and 3,4-ODA. Examples of dianhydrides thatincorporate some of these characteristics are 6FDA, BPADA, ODPA, DSDAand BODA.

In one embodiment, the solvated mixture (the substantially imidizedsolution) can be mixed with an amine precursor and a colorant, such as apigment or a dye, and then cast to form a polymer film. In oneembodiment, the colorant may be a low conductivity carbon black. Inanother embodiment, the solvated mixture (the first substantiallyimidized solution) can be precipitated with an antisolvent, such aswater or alcohols (e.g., methanol, ethanol, isopropyl alcohol). In oneembodiment, the precipitate can be washed to remove the catalyst. Afterwashing, the precipitate may be substantially dried, but need not becompletely dry. The polymer precipitate can be re-dissolved in a secondsolvent, such as methyl isobutyl ketone (MIBK), methyl ethyl ketone(MEK), tetrahydrofuran (THF), cyclopentanone, ethyl acetate, acetone,DMAc, NMP and mixtures thereof, to form a second substantially imidizedsolution (a casting solution). To the second substantially imidizedsolution, a precursor and a colorant can be added, which can then becast to form a polymer film.

In one embodiment, the substantially imidized polymer solution can becast or applied onto a support, such as an endless belt or rotatingdrum, to form a film. Alternatively, it can be cast on a polymericcarrier such as PET, other forms of Kapton® polyimide film (e.g.,Kapton® HN or Kapton OL films) or other polymeric carriers. Next, thesolvent-containing film can be converted into a film by heating topartially or fully remove the solvent. In some aspects of the invention,the film is separated from the carrier before drying to completion.Final drying steps can be performed with dimensional support orstabilization of the film. In other aspects, the film is heated directlyon the carrier.

In one embodiment, poly(amide-imides) can be formed by the reaction ofacyl chlorides with diamines and anhydrides.

In one embodiment, poly(ester-imides), or poly(amide-imides), can beformed using ester-containing, or amide-containing, diamines ordianhydrides in similar processes as those described above. In oneembodiment, a poly(ester-imide) can be formed by direct reaction of anester-containing diamine or dianhydride. In one embodiment, apoly(amide-imide) can be formed by direct reaction of anamide-containing diamine or dianhydride.

In one embodiment, poly(ester-imides) can be formed by esterification ofdiols with carboxylic acid-containing monomers with imide groups, asdescribed in U.S. Pat. No. 4,383,105.

The casting solution can further comprise any one of a number ofadditives, such as processing aids (e.g., oligomers), antioxidants,light stabilizers, flame retardant additives, anti-static agents, heatstabilizers, ultraviolet absorbing agents, inorganic fillers or variousreinforcing agents. Inorganic fillers can include thermally conductivefillers, metal oxides, inorganic nitrides and metal carbides, andelectrically conductive fillers like metals. Common inorganic fillersare alumina, silica, diamond, clay, talc, sepiolite, boron nitride,aluminum nitride, titanium dioxide, dicalcium phosphate, and fumed metaloxides. Low color organic fillers, such as polydialkylfluorenes, canalso be used. Common organic fillers include polyaniline, polythiophene,polypyrrole, polyphenylenevinylene, polydialkylfluorenes, carbon black,graphite, multiwalled and single walled carbon nanotubes and carbonnanofibers. In one embodiment, nanoparticle fillers and nanoparticlecolloids can be used.

In one embodiment, an electrically conductive filler is carbon black. Inone embodiment, the electrically conductive filler is selected from thegroup consisting of acetylene blacks, super abrasion furnace blacks,conductive furnace blacks, conductive channel type blacks, carbonnanotubes, carbon fibers, fine thermal blacks and mixtures thereof. Asdescribed above for low conductivity carbon black, oxygen complexes onthe surface of the carbon particles act as an electrically insulatinglayer. Thus, low volatility content is generally desired for highconductivity. However, it is also necessary to consider the difficultyof dispersing the carbon black. Surface oxidation enhancesdeagglomeration and dispersion of carbon black. In some embodiments,when the electrically conductive filler is carbon black, the carbonblack has a volatile content less than or equal to 1%.

Fillers can have a size of less than 550 nm in at least one dimension.In other embodiments, the filler can have a size of less than 500, lessthan 450, less than 400, less than 350, less than 300, less than 250, orless than 200 nm (since fillers can have a variety of shapes in anydimension and since filler shape can vary along any dimension, the “atleast one dimension” is intended to be a numerical average along thatdimension). The average aspect ratio of the filler can be 1 or greater.In some embodiments, the sub-micron filler is selected from a groupconsisting of needle-like fillers (acicular), fibrous fillers, plateletfillers, polymer fibers, and mixtures thereof. In one embodiment, thesub-micron filler is substantially non-aggregated. The sub-micron fillercan be hollow, porous, or solid. In one embodiment, the sub-micronfillers of the present disclosure exhibit an aspect ratio of at least 1,at least 2, at least 4, at least 6, at least 8, at least 10, at least12, or at least 15 to 1.

In some embodiments, sub-micron fillers are 100 nm in size or less. Insome embodiments, the fillers are spherical or oblong in shape and arenanoparticles. In one embodiment, sub-micron fillers can includeinorganic oxides, such as oxides of silicon, aluminum and titanium,hollow (porous) silicon oxide, antimony oxide, zirconium oxide, indiumtin oxide, antimony tin oxide, mixed titanium/tin/zirconium oxides, andbinary, ternary, quaternary and higher order composite oxides of one ormore cations selected from silicon, titanium, aluminum, antimony,zirconium, indium, tin, zinc, niobium and tantalum. In one embodiment,nanoparticle composites (e.g., single or multiple core/shell structures)can be used, in which one oxide encapsulates another oxide in oneparticle.

In one embodiment, sub-micron fillers can include other ceramiccompounds, such as boron nitride, aluminum nitride, ternary or higherorder compounds containing boron, aluminum and nitrogen, galliumnitride, silicon nitride, aluminum nitride, zinc selenide, zinc sulfide,zinc telluride, silicon carbide, and their combinations, or higher ordercompounds containing multiple cations and multiple anions.

In one embodiment, solid silicon oxide nanoparticles can be producedfrom sols of silicon oxides (e.g., colloidal dispersions of solidsilicon oxide nanoparticles in liquid media), especially sols ofamorphous, semi-crystalline, and/or crystalline silica. Such sols can beprepared by a variety of techniques and in a variety of forms, whichinclude hydrosols (i.e., where water serves as the liquid medium),organosols (i.e., where organic liquids serves as the liquid medium),and mixed sols (i.e., where the liquid medium comprises both water andan organic liquid). See, e.g., descriptions of the techniques and formsdisclosed in U.S. Pat. Nos. 2,801,185, 4,522,958 and 5,648,407. In oneembodiment, the nanoparticle is suspended in a polar, aprotic solvent,such as, DMAc or other solvent compatible with polyamic acid orpoly(amide amic acid). In another embodiment, solid nanosilica particlescan be commercially obtained as colloidal dispersions or sols dispersedin polar aprotic solvents, such as for example DMAC-ST (Nissan ChemicalAmerica Corporation, Houston Tex.), a solid silica colloid inN,N-dimethylacetamide containing less than 0.5 percent water, with 20-21wt % SiO2, with a median nanosilica particle diameter, d50, of about 16nm.

In one embodiment, sub-micron fillers can be porous and can have poresof any shape. One example is where the pore comprises a void of lowerdensity and low refractive index (e.g., a void-containing air) formedwithin a shell of an oxide such as silicon oxide, i.e., a hollow siliconoxide nanoparticle. The thickness of the sub-micron fillers shellaffects the strength of the sub-micron fillers. As the hollow siliconoxide particle is rendered to have reduced refractive index andincreased porosity, the thickness of the shell decreases resulting in adecrease in the strength (i.e., fracture resistance) of the sub-micronfillers. Methods for producing such hollow silicon oxide nanoparticlesare known, for example, as described in Japanese Patent Nos. 440692162and 403162462. Hollow silicon oxide nanoparticles can be obtained fromJGC Catalysts and Chemicals, LTD, Japan.

In one embodiment, sub-micron fillers can be coated with a couplingagent. For example, a nanoparticle can be coated with an aminosilane,phenylsilane, acrylic or methacrylic coupling agents derived from thecorresponding alkoxysilanes. Trimethylsilyl surface capping agents canbe introduced to the nanoparticle surface by reaction of the sub-micronfillers with hexamethyldisilazane. In one embodiment, sub-micron fillerscan be coated with a dispersant. In one embodiment, sub-micron fillerscan be coated with a combination of a coupling agent and a dispersant.Alternatively, the coupling agent, dispersant or a combination thereofcan be incorporated directly into the polymer film and not necessarilycoated onto the sub-micron fillers.

In some embodiments a coextrusion process can used to form a multilayerpolymer film with an inner core layer sandwiched between two outerlayers. In this process, a finished polyamic acid solution is filteredand pumped to a slot die, where the flow is divided in such a manner asto form the first outer layer and the second outer layer of athree-layer coextruded film. In some embodiments, a second stream ofpolyimide is filtered, then pumped to a casting die, in such a manner asto form the middle polyimide core layer of a three-layer coextrudedfilm. The flow rates of the solutions can be adjusted to achieve thedesired layer thickness.

In some embodiments, the multilayer film is prepared by simultaneouslyextruding the first outer layer, the core layer and the second outerlayer. In some embodiments, the layers are extruded through a single ormulti-cavity extrusion die. In another embodiment, the multilayer filmis produced using a single-cavity die. If a single-cavity die is used,the laminar flow of the streams should be of high enough viscosity toprevent comingling of the streams and to provide even layering. In someembodiments, the multilayer film is prepared by casting from the slotdie onto a moving stainless-steel belt. In one embodiment, the belt isthen passed through a convective oven, to evaporate solvent andpartially imidize the polymer, to produce a “green” film. The green filmcan be stripped off the casting belt and wound up. The green film canthen be passed through a tenter oven to produce a fully cured polyimidefilm. In some embodiments, during tentering, shrinkage can be minimizedby constraining the film along the edges (i.e., using clips or pins).

The thickness of the polymer film may be adjusted, depending on theintended purpose of the film or final application specifications. In oneembodiment, the polyimide film has a total thickness in a range of fromabout 10 to about 80 μm, or from about 10 to about 25 μm, or from about15 to about 25 μm.

In one embodiment, the polymer film has a b* of less than about 1.25, orless than about 1.0 or less than about 0.8 for a film thickness of about25 μm, when measured with a dual-beam spectrophotometer, using D65illumination and 10-degree observer, in total transmission mode over awavelength range of 360 to 780 nm. In one embodiment, the polymer filmhas a yellowness index (YI) of less than about 2.25, or less than about2.0 or less than about 1.75 for a film thickness of about 25 μm, whenmeasured using the procedure described by ASTM E313.

Conductive Layers

As used herein, the term “conductive layers”, or “conductive foils”,mean metal layers, or metal foils, (thin compositions having at least50% of the electrical conductivity of a high-grade copper). Conductivefoils are typically metal foils. Metal foils do not have to be used aselements in pure form; they may also be used as metal foil alloys, suchas copper alloys containing nickel, chromium, iron, and other metals.The conductive layers may also be alloys of metals.

Particularly suitable metallic substrates are foils of rolled, annealedcopper or rolled, annealed copper alloy. In many cases, it has proved tobe advantageous to pre-treat the metallic substrate before coating. Thispre-treatment may include, but is not limited to, electro-deposition orimmersion-deposition on the metal of a thin layer of copper, zinc,chrome, tin, nickel, cobalt, other metals, and alloys of these metals.The pre-treatment may consist of a chemical treatment or a mechanicalroughening treatment. It has been found that this pre-treatment enablesthe adhesion of the polyimide layer and, hence, the peel strength to befurther increased. Apart from roughening the surface, the chemicalpre-treatment may also lead to the formation of metal oxide groups,enabling the adhesion of the metal to a polyimide layer to be furtherincreased. This pre-treatment may be applied to both sides of the metal,enabling enhanced adhesion to substrates on both sides.

Inorganic Substrates

In one embodiment, inorganic substrates can be inorganic materialscontaining silicon and oxygen. Inorganic substrates can be crystallineinorganic materials or amorphous. Substrates can be films or layers, orother shapes (e.g., wedges, prisms), including any angular or curvedgeometric shape. Substrates can be rods, cylinders or plates. Autoclavelamination process can be especially suited to bonding non-planarmaterials to non-planar substrates. In one embodiment, inorganicsubstrates can include ceramic, glass or glass-ceramic materials, ormixtures thereof.

In one embodiment, ceramic substrates containing silicon and oxygen caninclude oxides, nitrides or oxy-nitrides, phosphides or oxyphosphides,carbides or oxycarbides. In some cases, the substrate may comprise asilicon oxide surface but have a different bulk composition away fromthe surface of the substrate. For instance, a Si₃N₄ or a SiC substratecan be hydrolyzed or oxidized so that it contains silicon and oxygen atthe surface. Multilayer inorganic substrates can also be used. Coatingsof silicon oxide or silicon- and oxygen-containing inorganic species canbe used on inorganic substrates. Coatings can be formed in a variety ofways, including physical vapor deposition, sputtering, atomic layerdeposition and the like. Coatings can also be made, which containsilicon and oxygen, by liquid-based coating processes (spray coating,slot die coating, bar coating), for instance using an alkoxysilane asone component in the coating. The surface on the inorganic substratedoes not have to have exclusively silicon and oxygen. A mixed phase orcombination of phases can be used, as long as the surface includessilicon and oxygen.

In one embodiment, inorganic substrates can be glass substrates ofvarious shapes and geometries. The term “glass” as used herein is meantto include any material made at least partially of glass, includingglass and glass-ceramics. “Glass-ceramics” include materials producedthrough controlled crystallization of glass. In some embodiments,glass-ceramics have about 30% to about 90% crystallinity. Non-limitingexamples of glass-ceramic systems that may be used includeLi₂O×Al₂O₃×nSiO₂ (i.e., LAS systems), MgO×Al₂O₃×nSiO₂ (i.e., MASsystems), and ZnO×Al₂O₃×nSiO₂ (i.e., ZAS systems).

In one or more embodiments, the inorganic substrate may include glass,which may be strengthened or non-strengthened. Examples of suitableglass include soda lime glass, alkali aluminosilicate glass,alkali-containing borosilicate glass and alkali aluminoborosilicateglass. In some variants, the glass may be free of lithia. In one or morealternative embodiments, the substrate may include crystallinesubstrates such as glass-ceramic substrates (which may be strengthenedor non-strengthened) or may include a single crystal structure, such assapphire. In one or more specific embodiments, the substrate includes anamorphous base (e.g., glass) and a crystalline cladding (e.g., sapphirelayer, a polycrystalline alumina layer and/or or a spinel (MgAl₂O₄)layer.

A substrate or layer may be strengthened to form a strengthenedsubstrate or layer. As used herein, the terms “strengthened substrate”or “strengthened layer” may refer to a substrate and/or layer that hasbeen chemically strengthened, for example through ion-exchange of largerions for smaller ions in the surface of the substrate and/or layer.Other strengthening methods known in the art, such as thermal tempering,or utilizing a mismatch of the coefficient of thermal expansion betweenportions of the substrate and/or layer to create compressive stress andcentral tension regions, may also be utilized to form strengthenedsubstrates and/or layers.

Where the substrate and/or layer is chemically strengthened by an ionexchange process, the ions in the surface layer of the substrate and/orlayer are replaced by, or exchanged with, larger ions having the samevalence or oxidation state. Ion exchange processes are typically carriedout by immersing a substrate and/or layer in a molten salt bathcontaining the larger ions to be exchanged with the smaller ions in thesubstrate. It will be appreciated by those skilled in the art thatparameters for the ion exchange process, including, but not limited to,bath composition and temperature, immersion time, the number ofimmersions of the substrate and/or layer in a salt bath (or baths), useof multiple salt baths, additional steps such as annealing, washing, andthe like, are generally determined by the composition of the substrateand/or layer and the desired compressive stress (CS), depth ofcompressive stress layer (or depth of layer) of the substrate thatresult from the strengthening operation. By way of example, ion exchangeof alkali metal-containing glass substrates and/or layers may beachieved by immersion in at least one molten bath containing a salt suchas, but not limited to, nitrates, sulfates, and chlorides of the largeralkali metal ion. The temperature of the molten salt bath typically isin a range from about 380° C. up to about 450° C., while immersion timesrange from about 15 minutes up to about 40 hours. However, temperaturesand immersion times different from those described above may also beused.

In addition, non-limiting examples of ion exchange processes in whichglass substrates and/or layers are immersed in multiple ion exchangebaths, with washing and/or annealing steps between immersions, aredescribed in U.S. Pat. No. 8,561,429, in which glass substrates arestrengthened by immersion in multiple, successive, ion exchangetreatments in salt baths of different concentrations; and U.S. Pat. No.8,312,739, in which glass substrates are strengthened by ion exchange ina first bath that is diluted with an effluent ion, followed by immersionin a second bath having a smaller concentration of the effluent ion thanthe first bath.

In one embodiment, a solution having amine reagent containing silicon isused to treat an inorganic substrate using a dip coating process. Theamine reagent containing silicon can have alkoxide groups. The aminereagent includes a primary or secondary amine, and after drying, theinorganic substrate has an amine-functional surface. Subsequently, thesubstrate can be laminated with heat and pressure to a polymer film,which includes a polymer having an imide group. The amine on theinorganic surface may react with the polymer to form an amide andprovide siloxane linkages to the substrate.

Curable Resin Coating Compositions

In one embodiment, a curable resin coating composition can be applied toa polymer film layer. In some embodiments, a curable resin coatingcomposition can be applied to an article including a polymer film layerand an inorganic substrate, wherein the curable resin coatingcomposition is applied to a surface of the polymer film layer on a sideopposite the inorganic substrate. In one embodiment, a curable resincoating composition comprises at least one curable oligomer and at leastone organic coating solvent. Suitable curable oligomers are any whichform a hard coat layer upon curing. As used herein, the term “hard coat”refers to a material, coating, or layer on a substrate that forms a filmupon curing having a higher pencil hardness than the substrate. Suchhard coat layers protect the underlying substrate from mechanicalabrasion and wear, and optionally enhances the self-cleaning propertiesof the surface.

Suitable curable oligomers useful in a curable resin coating compositioninclude, but are not limited to, (meth)acrylate oligomers, urethaneoligomers, (meth)acrylate-urethane oligomers, siloxane oligomers, andcombinations thereof. Liquid curable oligomers are preferred. Suitable(meth)acrylate oligomers include, without limitation, oligomerscomprising as polymerized units one or more (meth)acrylate monomerschosen from aliphatic monofunctional (meth)acrylate monomers andaliphatic multifunctional (meth)acrylate monomers. It is preferred thatthe present curable oligomer is chosen from (meth)acrylate oligomers,(meth)acrylate-urethane oligomers, siloxane oligomers, and combinationsthereof, more preferably from (meth)acrylate-urethane oligomers and asiloxane oligomer.

In some embodiments, the curable resin coating compositions may comprisea cured acrylate resin material derived from an actinic radiationcurable acrylic composition. The actinic radiation curable acryliccomposition can comprise (a) one or more, or two or more, or all threemultifunctional (meth)acrylate diluents chosen from (a1) an aliphatictrifunctional (meth)acrylate, preferably, acrylate, monomer, (a2) analiphatic tetrafunctional (meth)acrylate monomer, or (a3) an aliphaticpentafunctional (meth)acrylate preferably, acrylate, monomer; (b) from 3to 30, or from 10 to 30 wt %, based on the total weight of monomersolids, of one or more one (meth)acrylate, preferably, acrylate, monomercontaining an isocyanurate group; (c) from 5 to 60, from 5 to 55, from10 to 50, from 5 to 40, or from 10 to 40 wt % based on the total weightof monomer solids, of one or more aliphatic urethane (meth)acrylate,preferably, acrylate, functional oligomer having no fewer than 6 and upto 24, or from 6 to 12, or from 6 to 10 (meth)acrylate, preferably,acrylate, groups; (d) from 2 to 10, from 3 to 8, or from 3 to 7 wt %based on total monomer solids, of one or more radical initiators,wherein the total amount of monomer and functional oligomer solidsamounts to 100 wt %. The actinic radiation curable acrylic compositioncan further comprise (e) one or more organic solvents.

In some embodiments, the actinic radiation curable acrylic compositioncan comprise from 9 to 70, from 9 to 60, from 3 to 30, from 3 to 20, orfrom 3 to 15 wt % of (a) one or more, or two or more, or all threemultifunctional (meth)acrylate diluents chosen from (a1) an aliphatictrifunctional (meth)acrylate, preferably, acrylate, monomer (a2) analiphatic tetrafunctional (meth)acrylate monomer; or (a3) an aliphaticpentafunctional (meth)acrylate.

The radical initiators can include, but are not limited to,benzophenones, benzils (1,2-diketones), thioxanthones,(2-benzyl-2-dimethylamino-1-[4-(4-morpholinyl)phenyl]-1-butanone),2,4,6-trimethyl-benzoyl)-diphenyl phosphine oxide,1-hydroxy-cyclohexyl-phenyl-ketone,2-hydroxy-2-methyl-1-phenyl-1-propanone), oligomeric2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanones,dihydro-5-(2-hydroxy-2-methyl-1-oxopropyl)-1,1,3-trimethyl-3-(4-(2-hydroxy-2-methyl-1-oxopropyl)phenyl)-1H-indenes,and bis-benzophenones, or, preferably, oligomeric2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanones,dihydro-5-(2-hydroxy-2-methyl-1-oxopropyl)-1,1,3-trimethyl-3-(4-(2-hydroxy-2-methyl-1-oxopropyl)phenyl)-1H-indenes,orα-[(4-benzoylphenoxy)-acetyl]-w-[[2-(4-benzoylphenoxy)-acetyl]oxy]-poly(oxy-1,4-butanediyl)).The actinic radiation curable acrylic compositions of the presentapplication further comprises from 0.1 to 30, from 1 to 30, from 2 to30, from 3 to 30, from 10 to 30, from 3 to 25, from 5 to 25, or from 3to 20 wt % based on the total weight of (a), (b), (c) and (d), of one ormore thiol compounds of sulfur-containing polyol (meth)acrylates, orthiols not containing (meth)acrylate. Such compounds can be used topromote the surface cure of the actinic radiation cured coatings madefrom the present compositions. Suitable sulfur-containing polyol(meth)acrylates have at least 2, or at least 3, or 6 or fewer, or 5 orfewer, or from 2 to 6, (meth)acrylate functional groups. An exemplarysulfur-containing polyol (meth)acrylate can be a mercapto modifiedpolyester acrylate, sold as EBECRYL™ LED 02 or LED 01 (Allnex CoatingResins, Germany).

The actinic radiation curable acrylic composition comprises in total 5wt % or less, or 3.5 wt % or less, as solids, of inorganic nanoparticlecompounds, such as fillers, for example silica, alumina, ceria, titania,zirconia or any suitable metal or metal oxide nanoparticles having anaverage particle size of 1000 nm or less in diameter for the primaryparticle size, or 500 nm or less, or 100 nm or less at the longestdimension, measured by Brunauer-Emmett-Teller analyzer. Thenanoparticles can be symmetric, such as sphere, or non-symmetric, suchas rod. They can be solid or hollow, or mesoporous. The nanoparticlesmay be individually dispersed or can be dispersed as aggregates in thecomposition. When the nanoparticles used are agglomerates, they have asecondary average particle size of less than 10000 nm, as measured bydynamic laser light scattering.

In one embodiment, the actinic radiation curable acrylic compositioncomprises (a) a multifunctional (meth)acrylate diluent of the (a1) oneor more aliphatic trifunctional (meth)acrylate, preferably, acrylate,monomer, in the amount of from 3 to 25, from 3 to 20, or from 3 to 15 wt%, based on total monomer solids, wherein the total amount of monomerand functional oligomer solids amounts to 100%.

In another embodiment, the actinic radiation curable acrylic compositioncomprises (a) a multifunctional (meth)acrylate diluent of the (a2) oneor more aliphatic tetrafunctional (meth)acrylate, preferably, acrylate,monomer, in the amount of from 3 to 25, from 3 to 20, or from 3 to 15 wt%, based on total monomer solids, wherein the total amount of monomerand functional oligomer solids amounts to 100%.

In yet another embodiment, the actinic radiation curable acryliccomposition comprises (a) a multifunctional (meth)acrylate diluent ofthe (a3) one or more aliphatic pentafunctional (meth)acrylate,preferably, acrylate, monomer, in the amount of from 3 to 25, from 3 to20, or from 3 to 15 wt %, based on total monomer solids, wherein thetotal amount of monomer and functional oligomer solids amounts to 100%.

In some embodiments, the actinic radiation curable acrylic compositioncomprises at least one (c) aliphatic urethane (meth)acrylate functionaloligomer has a formula molecular weight of from 1400 to 10000, or from1500 to 6000 g/mol, wherein the reacted isocyanate (carbamate) contentof the composition, as solids, of the one or more (c) aliphatic urethane(meth)acrylate, preferably, acrylate, functional oligomer ranges from 5to 60, or from 10 to 50 wt %.

In some embodiments, the curable resin coating compositions may comprisesiloxane oligomers. Suitable siloxane oligomers are those disclosed inU.S. Patent Application Publication Nos. 2015/0159044 and 2017/0369654,and in U.S. Pat. Nos. 7,790,347 and 6,391,999. In one embodiment,preferred curable oligomers comprise polymerized units of formulaR1_(m)R2_(n)Si(OR3)_(4-m-n), wherein: R1 is a C5-20 aliphatic groupcomprising an oxirane ring fused to an alicyclic ring; R2 is a C1-20alkyl, C6-30 aryl group, or C5-20 aliphatic group having one or moreheteroatoms; R3 is a C1-4 alkyl group or C1-4 acyl group; m is 0.1 to2.0; and n is 0 to 2.0. When the siloxane oligomer contains siloxaneunits which are not identical, m and n are molar average values. It ispreferred that R1 contains at least 6 carbon atoms, preferably no morethan 15, preferably no more than 12, preferably no more than 10.Preferably, R1 comprises an oxirane ring fused to an alicyclic ringhaving 5 or 6 carbon atoms, preferably six carbon atoms, and morepreferably a cyclohexane ring. Preferably, R1 contains no elements otherthan carbon, hydrogen and oxygen. It is preferred that R1 is anepoxycyclohexyl (that is, a cyclohexene oxide) group linked to siliconby a —(CH₂)_(j)— group, where j is from 1 to 6, and preferably 1 to 4.Preferably, when R2 is alkyl it contains no more than 15 carbon atoms,more preferably no more than 12, and yet preferably no more than 10.When R2 is an aryl group it preferably contains no more than 25 carbonatoms, more preferably no more than 20, and yet preferably no more than16. The term “C5-20 aliphatic group having one or more heteroatoms”refers to a C5-20 aliphatic group having one or more of: a halogen suchas fluorine; an ester group such as an acrylate group, a methacrylategroup, a fumarate group, or a maleate group; a urethane group; and avinyl ether group. It is preferred that R2 is a C1-20 alkyl or C6-30aryl group, and more preferably C1-20 alkyl. In an alternate preferredembodiment, R2 is a C1-20 alkyl or a C5-20 aliphatic group having one ormore heteroatoms, and more preferably C1-20 alkyl. Preferably, when R3is alkyl, it is methyl or ethyl, and more preferably methyl. When R3 isacyl, it is preferably formyl or acetyl. Preferably, m is at least 0.2,and more preferably at least 0.5; preferably no greater than 1.75, andmore preferably no greater than 1.5. Preferably, n is no greater than1.5, more preferably no greater than 1.0, yet preferably no greater than0.8, and even more preferably n is zero. Suitable curable siloxaneoligomers are available from Polyset Company (Mechanicville, N.Y.).

Typically, the one or more curable oligomers are present in the curableresin coating composition in an amount of from 25 to 99 wt %, based onthe total weight of the composition excluding organic solvent.Preferably, the curable resin coating composition comprises a siloxaneoligomer in an amount of at least 28 wt %, preferably at least 29 wt %,preferably at least 30 wt %; preferably no more than 99 wt %, andpreferably no more than 65 wt %, based on the total weight of thecomposition excluding organic solvent. When the curable oligomer is asiloxane, it is preferred that the siloxane oligomer comprises from 25to 80 wt %, more preferably from 30 to 70 wt %, based on the totalweight of the composition excluding organic solvent. Preferably, thepresent curable resin coating compositions comprise from 50.1 to 100 wt% of the organic coating solvent described above and from 0 to 49.9 wt %of one or more secondary organic solvents, based on the total weight oforganic solvent. When one or more secondary organic solvents are used,they are preferably present in an amount of from 1 to 49.5 wt %,preferably from 2 to 40 wt %, and more preferably from 5 to 20 wt %,based on the total weight of organic solvents.

In one embodiment, reactive modifiers may be added to the curable resincoating composition to modify the formulation for performanceimprovement. Such reactive modifiers include, without limitation,flexibility modifiers, hardness modifiers, viscosity modifiers, opticalproperty modifiers, and the like. Preferably, the reactive modifiers arepresent in the resin composition in a total amount from 0 to 20 wt %;preferably at least 1 wt %, preferably at least 4 wt %, preferably atleast 8 wt %; preferably no more than 17 wt %, and preferably no morethan 15 wt %, based on the total weight of components in the compositionexclusive of organic solvent. Preferably, the reactive modifiercomprises at least two epoxycyclohexane groups or at least two oxetanerings, and more preferably two epoxycyclohexane groups.

In one embodiment, one or more commonly known other additives may beadded to the curable resin coating composition to further modifyproperties of the cured coating. Such optional additives include,without limitation, adhesion-promoters, leveling agents, defoamingagents, anti-static agents, anti-blocking agents, UV absorbers, opticalwhitening agents, anti-fingerprint additives, scratch resistanceadditives, and the like. Mixtures of two or more of such optionaladditives may be used in the compositions. These additives may be inliquid or solid form. Typically, each additive may be used in an amountof 0 to 5 wt %, and preferably from 0.1 to 5 wt %, and more preferablyfrom 1 to 3 wt %, based on the total weight of the composition. Scratchresistance additives may be used in an amount of from 5 wt %, preferably3 wt %, and more preferably 1.5 wt %, based on the total weight of thecomposition. A suitable amount of such scratch resistance additives isfrom 0 to 5 wt %, preferably from 0.1 to 3 wt %, and more preferablyfrom 0.1 to 1.5 wt %, based on the total weight of the composition.Scratch resistance additives may contain small amounts of inorganicparticles.

In one embodiment, curable resin coating compositions optionally containa curing agent, such as a photocuring agent, a thermal curing agent, ora combination thereof. Preferably, the curable resin coating compositioncomprises a photocuring agent, and more preferably a cationicphotoinitiator. Such curing agent is present in the curable resincoating compositions in an amount of from 0 to 8 wt %, based on thetotal weight of the composition excluding organic solvent, andpreferably from 0.5 to 7 wt %. Preferably, the curable resin coatingcomposition comprises at least 1 wt % of the cationic photoinitiator,preferably at least 1.5 wt %; preferably no more than 6 wt %, preferablyno more than 5 wt %, and preferably no more than 4.5 wt %. Preferredinitiators include, e.g., diaryliodonium salts and triarylsulfoniumsalts. Such curing agents are well-known to those skilled in the art andare generally commercially available from a variety of sources.Optionally, a photosensitizer may be used in combination with aphotocuring agent. Any suitable photosensitizer known in the art may beused. The selection of which photosensitizer and the amount thereof tobe used is within the ability of those skilled in the art.

In one embodiment, nanoparticles may optionally be, and preferably are,added to the present curable resin coating compositions. Suitablenanoparticles are inorganic nanoparticles and organic nanoparticles.When inorganic particles are used in the present curable resin coatingcompositions, they are used in an amount of from 35 to 66 wt %, based onthe total weight of the composition excluding organic solvent.Preferably, the curable resin coating composition comprises at least 40wt % non-porous nanoparticles of silica, a metal oxide, or a mixturethereof, preferably at least 42 wt %; preferably no more than 65 wt %,preferably no more than 64 wt %, preferably no more than 63 wt %. Theorganic nanoparticles may be present in the curable composition in anamount ranging from 0 to 10 wt %, preferably in an amount of at least0.1 wt %, preferably in an amount of up to 6 wt %, based on the totalweight of the resin composition excluding any organic solvent.Preferably, the organic nanoparticle is present in the curable resincoating composition in an amount of from 0.1 to 10 wt %, and morepreferably from 0.1 to 6 wt %, based on the total weight of thecomposition excluding any organic solvent. Suitable inorganicnanoparticles are non-porous nanoparticles chosen from silica, metaloxide, or a mixture thereof. Preferably, the non-porous nanoparticlesare silica, zirconium oxide, or a mixture thereof, and preferablysilica. Preferably, the surface area of the non-porous nanoparticles isat least 50 m²/g, preferably at least 60 m²/g; preferably no greaterthan 500 m²/g, preferably no greater than 400 m²/g. In general, thenon-porous nanoparticles of silica, a metal oxide, or a mixture thereof,the non-porous nanoparticles having an average particle diameter from 5to 50 nm. Preferably, the average diameter of the nanoparticles is atleast 10 nm, preferably at least 15 nm; preferably no greater than 40nm, preferably no greater than 35 nm. Preferably, the non-porousnanoparticles are functionalized with substituent groups that can reactwith the epoxy group of epoxy-siloxane oligomer under a cationic photocuring process or thermal curing condition. Preferred substituent groupsinclude, e.g., epoxy, acrylate, amino, vinyl ether, etc. Suitableorganic nanoparticles include, without limitation, core-shell rubber(CSR) nanoparticles. The optional CSR organic nanoparticles comprise arubber particle core and a shell layer, such CSR particles having anaverage diameter of from 50 to 250 nm. The shell layer of the CSRnanoparticles provides compatibility with the curable resin coatingcomposition and has limited swellability to facilitate mixing anddispersion of the CSR nanoparticles in the curable resin coatingcomposition. Suitable CSR nanoparticles are commercially available, suchas those available under the following tradenames: Paraloid EXL 2650 A,EXL 2655, EXL2691 A, available from The Dow Chemical Company, or KaneAce® MX series from Kaneka Corporation, such as MX 120, MX 125, MX 130,MX 136, MX 551, or METABLEN SX-006 available from Mitsubishi Rayon, orGenioperl P52 from Wacker Chemie AG.

In one embodiment, curable resin coating compositions comprise anorganic coating solvent chosen from: 2,6-dimethylcyclohexanone;2,4-dimethyl-3-pentanone; 2,4-dimethyl-3-pentanol;2,2,4,4-tetramethyl-3-pentanone; 2,6-dimethyl-4-heptanone; methyl2-hydroxy-2-methylpropanoate; isopropyl acetate; isoamyl acetate; andmixtures thereof, preferably comprise an organic coating solvent chosenfrom: 2,6-dimethylcyclohexanone; 2,4-dimethyl-3-pentanone;2,4-dimethyl-3-pentanol; 2,2,4,4-tetramethyl-3-pentanone;2,6-dimethyl-4-heptanone; methyl 2-hydroxy-2-methylpropanoate; isoamylacetate; and mixtures thereof, and more preferably comprise an organiccoating solvent chosen from: 2,6-dimethylcyclohexanone;2,4-dimethyl-3-pentanone; 2,4-dimethyl-3-pentanol;2,2,4,4-tetramethyl-3-pentanone; 2,6-dimethyl-4-heptanone; and methyl2-hydroxy-2-methylpropanoate; and mixtures thereof.

In one embodiment, curable resin coating compositions may comprise oneor more secondary organic solvents in addition to the one or moreorganic coating solvents described above. The one or more secondaryorganic solvents are different from the one or more organic coatingsolvents. A wide variety of organic solvents may be used as thesecondary organic solvent in the present compositions, provided that theorganic coating solvent is in the majority (>50 wt % of the solventmixture) and the secondary organic solvent is in the minority (<50 wt %of the solvent mixture). Suitable secondary organic solvents have from 3to 10 carbon atoms, and may be aliphatic or aromatic. Preferably, thesecondary organic solvent is aliphatic and more preferably a C3-10aliphatic compound having one or more oxygen atoms. Exemplary secondaryorganic solvents include, but are not limited to: 1-methoxypropan-2-ol(PGME); 1-ethoxypropan-2-ol (PGEE); 1-methoxy-2-methylpropan-2-ol;methyl lactate; ethyl lactate; methyl glycolate; 1-methoxy-propan-2-one;hydroxyacetone; 1,2-dimethoxyethane; 1,2-dimethoxypropane;1-methoxy-2-butanol; methyl 2-m ethoxyacetate; isopropanol;cyclopentanol; 2-methylbutan-1-ol; 4-methylpentan-2-ol;3-methylbutan-2-ol; toluene; and mixtures thereof.

In one embodiment, curable resin coating formulations can be prepared byfirst combining the desired amount of resin with the desired amount ofnanoparticle suspension in a 20-ml scintillation vial, followed bysonication (Fisher Scientific bath sonicator) and vortex mixing at roomtemperature until a homogenous mixture is obtained. When a nanoparticlesuspension is used, it is used as received or the suspension isconcentrated under vacuum at room temperature until ca. 95% of thesolvent had been removed as judged by loss in sample weight. New solventis then added as specified, and the mixture homogenized under sonicationand vortex mixing. Lastly, the desired amount of photoacid generator(PAG) is added into the solution. The final formulation is left on arotary mixer for at least 12 hours at room temperature to ensurehomogenous mixing before film casting.

Suitable methods for coating the curable resin coating compositioninclude, but are not limited to, spin-coating, curtain coating, spraycoating, roller coating, doctor blading, bar coating, dip coating, slotdie coating, and vapor deposition, among other methods. After casting,the coating is baked to remove the organic coating solvent and anyoptional secondary organic solvent. The selection of such bakingconditions is within the ability of those skilled in the art. Next, thecoating is cured, such as by heating or by exposure to actinic radiation(photocuring), and preferably by exposure to UV radiation, to form ahard coat film on the surface of the polymer film. In one embodiment,draw-down bars (manually or machine-operated) with different gap sizesare used to control film thickness of the hard coating when casting theprepared formulations on polymer films. The cast film is immediatelyheated to 90° C. on a hotplate for three minutes in a fume hood,followed by UV-curing (Fusion D-type bulb, four passes at a belt speedof 47 fpm). The average values for UV irradiance are around 3670, 960,280, 4360 mW/cm² in the UVA, UVB, UVC, and UVV regimes, respectively.The average values for energy density were ca. 480, 120, 40, and 570mJ/cm² in the UVA, UVB, UVC, and UVV regimes, respectively. Finally, thefilms are thermally cured for 2 hours at 87° C. in an oven afterUV-cure. In one embodiment, after curing, the adhesion-promoter at theinterface between the hard coat film and the polyimide film can bepartially or substantially intermixed with the hard coat film.

Lamination

Metal-clad laminates can be formed as single-sided laminates ordouble-sided laminates by any number of well-known processes. In oneembodiment, a lamination process may be used to form a metal-cladlaminate with a polymer film, such as a multilayer film. In oneembodiment, a first outer layer including a first thermoplasticpolyimide is placed between a first conductive layer and a core layer,and a second outer layer including a second thermoplastic polyimide isplaced on the opposite side of the core layer. In one embodiment, asecond conductive layer is placed in contact with the second outer layeron a side opposite the core layer. One advantage of this type ofconstruction is that the lamination temperature of the multilayer filmis lowered to the lamination temperature necessary for the thermoplasticpolyimide of the outer layer to bond to a conductive layer(s). In oneembodiment, the conductive layer(s) is a metal layer(s).

The amine reagent can be applied to the metal layer surface, the polymerfilm surface, or both surfaces. Any method to contact the metal layer orpolymer film with a soluble amine reagent can be used, including barcoating, slot die coating, spray coating, dip coating, spin coating orother liquid coating methods. In one embodiment, a surface of the metallayer, the polymer film layer, or both the metal and the polymer filmmay be plasma treated or corona treated before lamination to furtherenhance the adhesion of the polymer film layer to the inorganicsubstrate. Any plasma or corona treatment will be performed beforetreatment with an amine reagent. In one embodiment, a surface of themetal layer, the polymer film layer, or both the metal layer and thepolymer film may further include additional adhesion promoters that arenot amine reagents as described above.

one embodiment, prior to the step of applying a polymer film onto ametal foil, the polymer film can be subjected to a pre-treatment step.Pre-treatment steps can include, heat treatment, corona treatment,plasma treatment under atmospheric pressure, plasma treatment underreduced pressure, treatment with coupling agents like silanes andtitanates, sandblasting, alkali-treatment, acid-treatments, and coatingpolyamic acids. To improve the adhesion strength, it is generally alsopossible to add various metal compounds as disclosed in U.S. Pat. Nos.4,742,099; 5,227,244; 5,218,034; and 5,543,222, incorporated herein byreference.

In addition, (for purposes of improving adhesion) the conductive metalsurface may be treated with various organic and inorganic treatments.These treatments include using silanes, imidazoles, triazoles, oxide andreduced oxide treatments, tin oxide treatment, and surfacecleaning/roughening (called micro-etching) via acid or alkalinereagents.

In one embodiment, a metal-clad laminate can include the polymer filmthat is a multilayer film and a first metal layer adhered to an outersurface of the first outer layer of the multilayer film. In oneembodiment, a metal-clad laminate can include a second metal layeradhered to an outer surface of the second outer layer of the multilayerfilm. In one embodiment, the first metal layer, the second metal layeror both metal layers can be copper. In one embodiment, a metal-cladlaminate of the present invention comprising a double side copper-cladcan be prepared by laminating copper foil to both sides of themultilayer film.

The adhesion of the polymer film to the inorganic substrate or metallayer can be accomplished by heating while applying pressure in ahydraulic press. In some embodiments, the polymer film has a hard coatlayer present on one surface of the polymer film layer prior tolamination, and the inorganic substrate is adhered to the oppositesurface of the polymer film layer. Typically, the highest temperatureachieved during the lamination process is not less than 20° C. below theT_(g) of the polymer film layer. Higher temperatures can be used for thelamination, but at temperatures greater than 50° C. above the T_(g) ofthe polymer, some discoloration of the film can occur if the residencetime at the higher temperature is five minutes or more. Hence, highertemperature lamination may require residence times shorter than 5minutes. Lamination in the hydraulic press can be in air or under vacuumto help remove trapped air. When laminating a polymer film to a metallayer, the amine reagent can be applied to the metal layer surface, thepolymer film surface, or both surfaces. When laminating a polymer filmto an inorganic substrate, the amine reagent can be applied to theinorganic substrate surface, the polymer film surface, or both surfaces.Any method to contact the metal layer, inorganic substrate or polymerfilm with a soluble amine reagent can be used, including bar coating,slot die coating, spray coating, dip coating, spin coating or otherliquid coating methods. In one embodiment, one or more surfaces to belaminated together may be plasma treated or corona treated beforelamination to further enhance the adhesion of the polymer film layer tothe metal layer or inorganic substrate. Any plasma or corona treatmentwill be performed before treatment with an amine reagent. In oneembodiment, one or more surfaces of the metal layer, the inorganicsubstrate, and the polymer film layer may further include additionaladhesion promoters that are not amine reagents as described above. Inone embodiment, lamination is carried out at a temperature in a range offrom about 20 degrees below to about 50 degrees above the T_(g) of thepolymer film layer.

In one embodiment, a laminate can be formed using an autoclavelamination process. An autoclave is a high-temperature pressure vesselwhich can be used to produce laminate structures in a batch process. Thelaminate components are assembled prior to loading the pressure vesselchamber and are arranged in such a way that they do not move while underheat and pressure. The process generally operates using air or an inertgas such as argon or nitrogen to provide the pressure to laminate thematerials inside the pressure vessel chamber. The gas inside is thenheated and cooled through different cycles using a heat exchanger tomaintain different temperature and pressure profiles for set periods oftime. In one embodiment, process cycles will range from about 100 toabout 400 psig and from about 100 to about 400° C. with total cycle timeaccumulating up to about 30 hours. After the cycles are complete and thechamber is returned to ambient temperature and pressure the contents areremoved. In one embodiment, autoclave lamination is carried out at atemperature in a range of from about 20 degrees below to about 50degrees above the T_(g) of the polymer film layer.

In one embodiment, a roll-to-roll process may be used to form thelaminate articles of the present invention. In such a process, thepolymer film layer is supplied from a roll and first passes over atension roll along with the inorganic substrate or metal layer. Eitherone or both surfaces can be treated with the amine reagent.

In one embodiment, nip-roll lamination may be used, wherein nip rollsmay be heated to promote bonding of the polymer film layer to theinorganic substrate or metal layer. The bonding pressure exerted by thenip rolls may vary with the film materials, the polymeric materials, andthe temperatures employed. Proper control of the speed and the tensionwill minimize wrinkling of the film. In one embodiment, the temperatureof the nip rolls is in a range of from about 20 degrees below to about50 degrees above the T_(g) of the polymer film layer.

After bonding, the laminate is passed over a series of cooling rollswhich ensure that the laminate taken up on a roll is not tacky. Processwater cooling is generally sufficient to achieve this objective. Tensionwithin the system may be further maintained using idler rolls. Laminatearticles made through this process will have sufficient strength toallow for further handling by laminators that may add additional layersto the laminate.

Applications

In one embodiment, the polymer compositions of the present invention areuseful as films for die pad bonding of flexible print connection boardsor semiconductor devices or packaging materials for CSP (chip scalepackage), chip on flex (COF), COL (chip on lead), LOC (lead on chip),multi-chip module (“MCM”), ball grid array (“BGA” or micro-ball gridarray), and/or tape automated bonding (“TAB”).

In another embodiment, the polymer films of the present invention may beused for wafer level integrated circuit packaging, where a composite ismade using a polymer film according to the present invention interposedbetween a conductive layer (typically a metal) having a thickness ofless than 100 μm, and a wafer comprising a plurality of integratedcircuit dies. In one (wafer level integrated circuit packaging)embodiment, the conductive passageway is connected to the dies by aconductive passageway, such as a wire bond, a conductive metal, a solderbump or the like.

In one embodiment, articles having inorganic substrates and polymer filmlayers, such as glass or ceramic laminates, can be used asimpact-resistant laminates for structural, or architectural,applications, such as hurricane-resistant windows, theft-resistantpanels and blast-resistant structures. For example, glass beams,composed of laminated glass, usually provide poor post-breakagerobustness if all plies are broken. Articles that combine inorganicsubstrates with ductile polymer layers can improve the structuralperformance after failure and expand the scope of applications for theselaminates. In one embodiment, structural laminates having inorganicsubstrates and polymer film layers can also be used as sound-reducinglaminates, such as sound insulating panels.

In one embodiment, articles having inorganic substrates and polymer filmlayers can be used in applications for penetration-resistant laminates,such as bulletproof glass and armor. For example, bulletproof glass is astrong and optically transparent material that is particularly resistantto penetration by projectiles and can benefit from the less rigidproperties of the polymer layer in a multilayer film. In one embodiment,a ceramic substrate, such as single-crystal sapphire, aluminumoxynitride or other oxynitrides and spinel ceramics, can be laminated toa polymer film layer and used as transparent armor. In some cases, theseceramic laminates can greatly reduce the weight of armor while providingthe same penetration resistance as glass laminates.

In one embodiment, articles having inorganic substrates and polymer filmlayers can be used in architectural applications or transportationapplication where a combination of impact resistance, penetrationresistance and sound reduction are desired. For example, a windshield ona vehicle may include one or more inorganic substrates and one or morepolymer film layers that provide the windshield with a desired impactresistance, penetration resistance and sound insulation.

In one embodiment, articles having inorganic substrates and polymer filmlayers can be used as panels for electronic devices, such as displaysfor consumer electronic devices.

In one embodiment, the polymer compositions of the present invention areuseful as shaped bodies, such as sheets, rods, tubes, rings, ball andcustom shaped parts. These shaped bodies can be used in applications,such as for bearings, bushings, gaskets and gasket rings, guides, valveseats, shut-off valves, brake linings, valves in turbochargers orcompressors, bearing components such as cages or balls, spark plugs,test sockets and wafer holders in the electronics industry, electricaland thermal insulation components, piston rings for compressors,pressure rings for gearboxes, radiation- and chemical-resistant pipeseals, friction linings, synthetic resin-bound diamond tools or ferrulesin gas chromatography and other thermoplastic injection molded partswhere chemical, electrical, thermal or wear resistance is needed. Insome embodiments, transparent polymer compositions can be used inapplications, such as for visors, protective eyewear, goggles,transparent shields, glasses, view ports, headlight housings andlighting fixtures, camera parts and other lenses that take advantage ofthe good optical properties of these transparent polymer compositions.

The advantageous properties of this invention can be observed byreference to the following examples that illustrate, but do not limit,the invention. All parts and percentages are by weight unless otherwiseindicated.

EXAMPLES Test Methods

Measurement of CIE L*, a*, b* Color

Color measurements were performed using a ColorQuest® XE dual-beamspectrophotometer (Hunter Associates Laboratory, Inc., Reston, Va.),using D65 illumination and 10 degree observer, in total transmissionmode over a wavelength range of 380 to 780 nm. Percent haze andtransmittance were also measured using this instrument.

Yellowness Index

Yellowness Index (YI) was measured using the procedure described by ASTME313.

Glass Transition Temperature

Glass transition temperature (T_(g)) was measured using dynamicmechanical analysis (Q800 DMA, TA Instrument) and is determined by thechange in slope of the storage modulus. This change is calculated fromthe intercept of two lines on a graph of the storage modulus withtemperature. The first line is the glassy plateau of the storage modulusbelow the transition region, and the second line is the sudden drop ofthe storage modulus in the transition region.

Thickness

Film thickness was determined by measuring 5 positions across theprofile of the film using a contact-type FISCHERSCOPE MMS PC2 modularmeasurement system thickness gauge (Fisher Technology Inc., Windsor,Conn.).

Polymer Synthesis

All glassware was dried at 160° C. overnight. The monomers (except for1,6-diaminohexane) were dried under vacuum for 12 hours at 160° C.

For the polyamic acid solution (PAA) with a monomer composition of 6FDA1.0//TFMB 0.5/HMD 0.5 (molar equivalents), 410 g of anhydrous DMAc wascombined with 40.0 g of trifluoromethylbenzidine (TFMB, Seika Corp.,Wakayam Seika Kogyo Co., LTD., Japan) and 14.52 g of 1,6-diaminohexane(HMD, TCI America, Portland, Oreg.) in a 1-L bottle. A second bottlecontaining 254 g DMAc was used for rinsing and was used and added, inits entirety, to the reaction vessel below.

A 1-L reaction vessel equipped with mechanical stirring and nitrogenpurged atmosphere was used. The reaction vessel was equipped with awater-cooling jacket. The above solution of TFMB/HMD in DMAc was addedto the reaction vessel along with the second bottle of DMAc (rinsesolvent) described above. The solution was cooled to 10° C., and 109.65g of 4,4′-(hexafluoroisopropylidene)diphthalic anhydride (6FDA, SynasiaInc., Metuchen, N.J.) was added in a controlled fashion to keep thetemperature of the reaction kettle at 25° C. Additional aliquots of 6FDAwere used to bring the viscosity of the solution to approximately 360poise. A total of 2.903 g of additional 6FDA monomer was added.

To prepare a substantially imidized solution, 4.0 molar equivalents ofbeta-picoline and 4.0 molar equivalents of acetic anhydride were addedto the polyamic acid solution. Hence, to 820.82 g of polyamic acidsolution, 92.22 g of beta-picoline and 101.09 g of acetic anhydride wereadded. The mixture was then stirred for 8 hours at 45° C., allowed tocool to room temperature for approximately 12 hours, and then heated foran additional 8 hours at 45° C. and again allowed to cool to roomtemperature.

Example 1

For Example 1 (E1), 2.68 g of a 20 wt % solution ofN-Boc-1,6-hexanediamine (TCI America, Portland Oreg.) in DMAc was addedto 50 g of the 16.4 wt % polymer solution and was mixed using acentrifugal-planetary mixer at 2200 rpm for 8 minutes. The solution wasthen de-gassed using the centrifugal-planetary mixer to force the gasfrom the polymer at 2000 rpm for 4 minutes.

The solution was cast onto a glass substrate at 25° C. to produce −1 mil(25 μm) dry films. The film on the glass substrate was heated to 65° C.for 20 min then to 85° C. for 30 min on a hotplate and then allowed tocool to room temperature. The film was released using a razor andmounted onto a 4×8 inch pin frame and placed in a furnace (CarboliteGero, Sheffield, UK). The furnace was then purged with nitrogen andheated according to the following temperature protocol:

-   -   25 to 90° C. (7° C./min), hold at 90° C. for 5 minutes;    -   90 to 150° C. (7° C./min), hold at 150° C. for 10 minutes;    -   150 to 250° C. (7° C./min), hold at 250° C. for 20 minutes.

The film was removed “hot” from the oven after heating to 250° C. for 20minutes and allowed to cool in air.

Inorganic substrates were treated in a silane solution. To a solution ofMeOH/deionized water (95/5 v/v, 100 gm) in a Pyrex® bottle was added 2 gof 3-(2-aminoethylamino) propyltrimethoxysilane (AEAPTMS) to form a 2%wt AEAPTMS solution. The solution was shaken several times and left toage overnight. 50×50×0.7 mm borosilicate glass substrates (Corning®EAGLE XG® Slim Glass, Corning Inc., Corning, N.Y.) were rinsed withwater, acetone and then methanol, and then the substrates were submergedin a glass container containing the silane solution. After 2 minutes ofgentle agitation, the substrates were removed and rinsed with methanol,held endwise on paper towels to allow excess solvent to wick away, airdried and then placed on a hotplate for 10 minutes at 110° C.

A laminate of a polymer film on inorganic substrate was formed in thefollowing manner. The polyimide film and glass were wiped with apolyester wipe (AlphaWipe® TX1009, Texwipe, Kernersville, N.C.) wet withisopropyl alcohol. A sandwich construction was assembled which includedthe following layers: metal plate (3 mm)/reinforced silicone rubbersheet (3 mm)/polyimide film (125 μm, Kapton® H)/Kapton® Film (HH) (25μm)/2×2″ polyimide film (modified for low T_(g))/borosilicate glasssubstrates (Corning® EAGLE XG® Slim Glass, 0.7 mm)/2×2″ polyimide film(modified for low T_(g))/Kapton® H (125 μm)/reinforced silicone rubbersheet (3 mm)/metal plate (3 mm). The stack was loaded into a 6″ benchtoppress (Auto C-PL, H, Carver, Inc., Wabash, Ind.) at a temperature of220° C. The sample was allowed to reach the platen temperature beforethe platens were completely closed and pressure was applied. The samplewas heated for a predetermined time, removed from the press hot, andallowed to cool under ambient conditions. Table 1 lists the temperature,pressure and time for the sample. To test for adhesion, the untreatededge of each sample was used to manually pull apart the laminate. A“pass” indicates that the laminate was resistant to separation, while a“fail” indicates that the laminate readily pulled apart with littleresistance.

Example 2

For Example 2 (E2), the same procedure as described in E1 was followed,except the initial lamination force and the lamination time were bothincreased.

Comparative Example 1

For Comparative Example 1 (CE1), 1.34 g of 20 wt % ofN-Boc-1,6-hexanediamine in DMAc was added to 50 g of the 16.4 wt %polymer solution and was mixed using the centrifugal-planetary mixer at2200 rpm for 8 minutes. The solution was then de-gassed using thecentrifugal-planetary mixer to force the gas from the polymer at 2000rpm for 4 minutes.

A polymer film and laminate of CE1 were prepared following the proceduredescribed above for E1, except that the film was dried to 200° C. forlamination.

Comparative Example 2

For Comparative Example 2 (CE2), the same procedure as described in CE1was followed, except the initial lamination force was decreased.

TABLE 1 Substrate T P_(init) P_(5 min) P_(25 min) Total Time ExamplePretreatment (° C.) (psi) (psi) (psi) (minutes) Adhesion CE1 AEAPTMS 200425 525 625 30 Fail CE2 AEAPTMS 200 400 525 650 30 Fail E1 AEAPTMS 220425 500 600 30 Pass E2 AEAPTMS 220 1250 1350 1950 60 Pass

Table 1 shows that good adhesion of polymer films to inorganicsubstrates can be achieved with proper selection of the laminationconditions. Because the lamination of the benchtop press is notdynamically controlled, the change in the pressure with lamination timeis noted.

Table 2 shows the optical properties of the polymer/glass laminate of E2compared to the 0.7 mm glass substrate before lamination.

TABLE 2 YI E313 Haze % Transmittance Transmittance Example L* a* b*[D65/10] [D65/10] (380-780 nm) (550 nm) E2 95.92 −0.54 1.93 3.25 1.8987.52 90.09 glass 96.80 0.04 0.18 0.36 0.27 91.87 92.01

Examples 3 to 6 and Comparative Example 3

For Examples 3 to 6 (E3-6), a soluble substantially imidized polyimideresin having the same composition as described in the Polymer Synthesisabove (6FDA 1.0//TFMB 0.5/HMD 0.5) was prepared in a larger batch,combined with T_(g) reducing compounds having an amine group asdescribed below and cast to form films. Methanol was used as anantisolvent to precipitate the resin. An excess of methanol was slowlyadded to the solution. The resulting slurry was filtered to isolate theresin and washed at least four times with methanol. The isolated resinwas dried in a vacuum oven at 90° C. for at least 16 hours. ForComparative Example 3 (CE3), a soluble substantially imidized polyimideresin with the same composition (6FDA 1.0//TFMB 0.5/HMD 0.5) wasprepared in a roll-to-roll process, but no T_(g) reducing compoundhaving an amine group was added when making the film.

For E3, a 16 wt % solution of the substantially imidized polyimide resinin DMAc was prepared. 15 g of this solution was combined with 0.440 g ofJeffamine® M600. The solution was cast onto a glass substrate at 25° C.to produce −1 mil (25 μm) dry films. The film on the glass substrate washeated to 65° C. for 20 min then to 85° C. for 30 min on a hotplate andthen allowed to cool to room temperature. The film was released using arazor and mounted onto a 4×8 inch pin frame and placed in a furnace. Thefurnace was then purged with nitrogen and heated according to thefollowing temperature protocol:

-   -   25 to 90° C. (7° C./min), hold at 90° C. for 5 minutes;    -   90 to 150° C. (7° C./min), hold at 150° C. for 10 minutes;    -   150 to 180° C. (7° C./min), hold at 180° C. for 20 minutes.

The film was removed “hot” from the oven after heating to 180° C. for 20minutes and allowed to cool in air.

For E4, a 15.9 wt % solution of the substantially imidized polyimideresin in DMAc was prepared. 15 g of this solution was combined with0.155 g of trans-N-Boc-1,4-cyclohexanediamine (Thermo Fisher, Waltham,Mass.), and a film was prepared as described above for E3.

For E5, a 15.9 wt % solution of the substantially imidized polyimideresin in DMAc was prepared. 15 g of this solution was combined with 1.16g of a 20.5 wt % solution of N-Boc-1,6-hexanediamine in DMAc, and a filmwas prepared as described above for E3.

For E6, a 15.9 wt % solution of the substantially imidized polyimideresin in DMAc was prepared. 15 g of this solution was combined with 0.4g of a 20.0 wt % solution of N-Boc-1,6-hexanediamine in DMAc, and a filmwas prepared as described above for E3.

For CE3, a 15.9 wt % solution of the substantially imidized polyimideresin in DMAc was prepared. 15 g of this solution was used to prepare afilm as described above for E3.

TABLE 3 Mole T_(g) ΔT_(g) Example T_(g) Reducing Compound (%) (° C.) (°C.) E3 Jeffamine ® M600 16.1 157 −51 E4trans-N-Boc-1,4-cyclohexanediamine 16.0 164 −44 E5N-Boc-1,6-hexanediamine 22.4 173 −35 E6 N-Boc-1,6-hexanediamine 8.9 187−21 CE3 none 0 208 —

As shown in Table 3, introduction of T_(g) reducing compound having anamine group results in a significant reduction in the T_(g) of thepolymer film.

What is claimed is:
 1. A polymer composition comprising a first polymerderived from: a soluble polymer composition comprising an imide group;and a T_(g) reducing compound comprising an amine group, wherein thefirst polymer has a glass transition temperature that is lower than asecond polymer derived from the same soluble polymer composition, butwithout a T_(g) reducing compound comprising an amine group.
 2. Thepolymer composition of claim 1, wherein the soluble polymer compositioncomprising an imide group is selected from the group consisting ofpolyimides, poly(amide-imides), poly(ether-imides), poly(ester-imides),copolymers comprising amide, ester or ether groups, and mixturesthereof.
 3. The polymer composition of claim 1, wherein the T_(g)reducing compound comprises an amine moiety comprising an amine or afirst masked amine that can be converted to form an amine, wherein thefirst masked amine can be chemically converted, thermally converted,photo-converted or dissociated.
 4. A polymer film comprising the polymercomposition of claim
 1. 5. A metal-clad laminate comprising the polymerfilm of claim 4 and a metal layer.
 6. An article comprising the polymerfilm of claim 4 and an inorganic substrate, wherein the inorganicsubstrate comprises a material comprising a ceramic, a glass, aglass-ceramic or a mixture thereof, wherein the material comprises: ametal cation selected from the group consisting of silicon, aluminum,titanium, zirconium, tantalum, niobium and mixtures thereof; and oxygen.7. The article of claim 6, further comprising a hard coat layer adheredto the polymer film layer on a side opposite the inorganic substrate. 8.An impact-resistant article comprising the article of claim
 6. 9. Apenetration-resistant article comprising the article of claim
 6. 10. Asound-reducing article comprising the article of claim
 6. 11. A coatingsolution comprising: a soluble polymer comprising an imide group; and aT_(g) reducing compound comprising: an amine moiety that can be an amineor a first masked amine that can be converted to an amine, wherein thefirst masked amine can be chemically converted, thermally converted,photo-converted or dissociated.
 12. The coating solution of claim 11,wherein the first masked amine is selected from the group consisting ofcarbamates, N-alkyl amines, N,N-dialkyl amines, N-aryl amines,N,N-diaryl amines, benzyl amines, amides, sulfonamides, ammonium saltsmade from acids and silyl derivatives.
 13. The coating solution of claim11, wherein the T_(g) reducing compound is selected from a singlemulti-functional precursor, a combination of multiple single-functionalprecursors, or a mixture thereof.
 14. The coating solution of claim 11,wherein the soluble polymer is selected from the group consisting ofpolyimides, poly(amide-imides), poly(ether-imides), poly(ester-imides),copolymers comprising amide, ester or ether groups, and mixturesthereof.